SAE论文
SAE论文 2009-01-1795
2009-01-1795Development of Specific Tools for Analysis andQuantification of Pre-ignition in a Boosted SI EngineJean-Marc Zaccardi, Laurent Duval and Alexandre PagotIFP Copyright © 2009 SAE InternationalABSTRACTRecent developments on highly downsized spark ignition engines have been focused on knocking behaviour improvement and the most advanced technologies combination can face up to 2.5 MPa IMEP while maintaining acceptable fuel consumption. Unfortunately, knocking is not the only limit that strongly downsized engines have to confront. The improvement of low-end torque is limited by another abnormal combustion which appears as a random pre-ignition. This violent phenomenon which emits a sharp metallic noise is unacceptable even on modern supercharged gasoline engines because of the great pressure rise that it causes in the cylinder (up to 20 MPa).The phases of this abnormal combustion have been analysed and a global mechanism has been identified consisting of a local ignition before the spark, followed by a propagating phase and ended by a massive auto-ignition. This last step finally causes a steep pressure rise and pressure oscillations.One of our objectives was to evaluate the sensitivity of an engine to pre-ignition regarding its design and settings. Therefore, in addition to our comprehension work, we have developed a first methodology based upon robust statistics to define new reliable and repeatable criteria to quantify this stochastic pre-ignition but also to detect each of its occurrence, suggesting the possibility of an on-line detection during steady state and transient operation as well. The statistical approach also showed that the distributions of well chosen combustion indicators are strongly altered by pre-ignitions. A second methodology was then defined to evaluate the influence of different parameters on pre-ignition by quantifying this alteration. This analysis notably gives the opportunity to achieve a deeper analysis of pre-ignition during engine development on test bench.INTRODUCTIONSpark ignition engines used today offer the great advantage of limiting local pollutants emissions (HC, CO & NOX) thanks to the excellent adequacy between their operating mode (lambda one) and their simple and low cost after-treatment system. Despite this fundamental asset, those engines are badly considered concerning the greenhouse gases emissions because competitor Diesel engines reach an average CO2emissions 20 % lower thanks to an overall good efficiency.Fuel consumption of SI engines has now to be reduce to meet future CO2legal emission agreements but also environmentally-friendly customer demands. In light of this, the combination of air charging and downsizing is one of the most promising solution because of its low technological cost and because it helps to reduce pumping and friction losses.Unfortunately, the combustion mechanism of SI engines can be disturbed by abnormal phenomena [1]. Two major kinds of uncontrolled combustion can appear. •Surface ignition : in this case, the ignition of fresh mixture is not controlled by a spark at a predetermined crank angle. This ignition takes place at variable timing on an overheated component (likea valve or a spark plug) because of the unbalancedthermal transfer between the energy brought by thecombustion and the thermal dissipation within theengine. The main feature of this kind of pre-ignition isthat it progressively degenerates since the overheated component is getting warmer and warmer cycle after cycle as a consequence of theearly timing combustion (hence it is generally calleda "run away pre-ignition"). This first abnormalcombustion can be fought with an optimised combustion chamber using for example an adaptedthermal range for the spark plug and improving thecooling circuit to remove potential hot surfaces.•A uto-ignition of fresh charge : this self ignition is a consequence of appropriate thermodynamic conditions inside the combustion chamber. Indeed, ifthe fresh mixture is strongly compressed and heatedup the auto-ignition delay can be reduced. Knockingand C A I combustion modes (Controlled A uto Ignition) are the best known examples of auto-ignition.More recently, developments of highly charged gasoline engines showed that a violent form of sporadic pre-ignition can appear under high loads at low engine speeds. Because of its occasional characteristic, this new kind of uncontrolled combustion does certainly not correspond to a classical surface pre-ignition.This phenomenon has already been mentioned and described in numerous previous papers. Our aim is notto discuss the potential causes of this pre-ignition. In fact, many hypotheses have already been formulated to explain this phenomenon but no one has really been confirmed and it is possible that several factors could be combined to provoke this dangerous combustion as well [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13].We focus here on new methodologies of analysis, quantification and control of this violent combustion. The aim is of course to minimize its occurrence frequency and its intensity in order to reach safely higher low end torque and to maximise the consumption reduction with a highly downsized engine.The first part of this paper gives a description of pre-ignition based upon cylinder pressure analysis and directin-cylinder imaging.The second part introduces the statistical data processing that has been used to characterize this phenomenon.Then, the third and fourth parts describe two strategies usable on board and on test bench to achieve a real-time detection and control of pre-ignition.EXPERIMENTAL APPARATUSENGINEResults shown in this paper were obtained on a single cylinder engine used at IFP for combustion studies and especially for highly charged SI engines. The main features of our selected technical definition are summarized in Table 1 and a simplified CAD view of thecombustion chamber is given in Figure 1.Figure 1 : CAD view of the pent roof cylinder headType Pent roof shape4 valvesBore (mm) 69Stroke (mm) 80.5Displacement (cm3) 301 Compression Ratio 9.5:1Connecting rod length (mm) 139Piston shape FlatIntake duration (CAD at 1 mm) 190Inlet Valve Opening (CAD at 1 mm) 10 ATDCMaximum intake valve lift (mm) 7.3Exhaust duration (CAD) 210Exhaust Valve Closure (CAD at 1 mm) 10 BTDCMaximum exhaust valve lift (mm) 8.2Table 1 : Engine specificationsManifold Port Fuel Injection and Direct Injection (DI)modes were used on this engine. The gasoline direct injection was performed with a multi-hole injector placedunder the intake ducts with a special spray targeting. The characteristics of this injector are summarized inTable 2.Injector type Multi-hole – 6 holes Oval sprayInjection pressure 6 – 20 MPaStatic flow 720 g/min @ 10 MPa (n-heptane)Single beam angle 16 °Table 2 : Multi-hole injector specificationsThe ignition was realised with a high energy DELPHI ignition coil (110 mJ) combined with a centrally located NGK spark plug which had an iridium centre electrode and a heat rating number of 8 (NGK rating).Rotating and reciprocating forces were balanced to achieve safely our full load objectives of 3.0 MPa IMEP at 1000 rpm and 2.5 MPa IMEP at 5500 rpm (115 kWi/L).TEST BENCHThis study was realised on a special test bench designed for single cylinder engines. Oil, coolant and fuel were supplied by electrically driven pumps. Several temperature and pressure measurements were made on the coolant, oil, fuel, intake and exhaust circuits to settle the different operating points and to supervise the engine.Intake pressure was recorded with an absolute pressure transducer (KULITE XT-123B-190-50A). Exhaust and in-cylinder pressures were recorded with water-cooled relative pressure transducers (A VL QC43D & KISTLER 6043A60).There was no turbocharger on our engine, but the test bench was equipped with a compressor for the intake line (sonic flow meter up to 0.35 MPa abs) and a flap in the exhaust line to simulate the backpressure of a turbine.There was no ECU associated to this engine. I njection and ignition were manually controlled with a specific software developed at IFP. This way, we could control the engine as we want for steady state running conditions even with multiple injection and ignition timings during the same cycle.All the measurements were recorded and analysed with an in-house software.PRE-IGNITION PROCESSDESCRIPTION BASED UPON CYLINDER PRESSUREWe propose here to sum up the description of the abnormal combustion process based upon cylinder pressure analysis. A full description is already available in a previous paper [2].The observation of this uncontrolled combustion on test bench is actually mainly made on in-cylinder pressure traces. A simple example with a violent pre-ignition compared to a normal combustion is given in Figure 2. Cycles n° 8 and 10 show a normal combustion with an initiation at the spark plug and a flame propagation through the combustion chamber. In this two cycles, we can observe the late ignition and hence combustion timing necessary to cope with the knocking phenomenon. Cycle n° 9 is an example of pre-ignition. The pressure difference between cycles n° 9 on the first hand and n° 8 and 10 on the other hand just before the spark is an obvious evidence that combustion began too early.Figure 2 : Pre-ignition exampleThis kind of pre-ignition can be so violent that a single occurrence can definitively damage the moving parts (especially the connecting rod). This abnormal combustion is all the more dangerous that it is impossible to fight against it simply by setting differently the spark advance or the air fuel ratio contrary to a classical knocking combustion.A simplified rate of heat release ROHR can be calculated from the cylinder pressure and combustion chamber volume (see Figure 3).⎟⎟⎠⎞⎜⎜⎝⎛−+−=dVPdPVVROHRcyl**1**11*1γγγγ : polytropic coefficientP : cylinder pressure (MPa)V : combustion chamber volume (dm3)Vcyl: displacement (dm3)Then, based upon the cylinder pressure and this simplified ROHR analyses, it is possible to propose a three steps general mechanism for pre-ignition [2].1. The ignition takes place before the spark occurrencewith a variable timing for each pre-ignition and anywhere in the combustion chamber (as far as we know using only one in-cylinder pressure transducer).2. Disregarding the early timing, the second part of thecombustion seems to be quite normal with a heat release which is comparable to a normal combustion.3. The third and last part of combustion is clearly fasterthan the second part. The pre-ignition somewhere in the combustion chamber combined with the compression at high load provoke such an increase of temperature and pressure that a bulk auto-ignition occurs.Figure 3 : Pre-ignition general mechanismThe final bulk auto-ignition looks like a knocking combustion except that the fresh mixture quantity concerned by this auto-ignition is far greater than for a classical knocking phenomenon (sometimes more than 50 % of the total fresh mixture quantity).Pressure oscillations are not clearly visible in the previous example because cylinder pressure was recorded at each crank angle degree. A ten times faster data acquisition rate can illustrate those pressure oscillations (see Figure 4). Besides, our analysis showed that those oscillations have roughly the same frequency content of a classical knocking combustion obtained on the same engine and evaluated beforehand from Bessel functions. Moreover, parasitic mechanical resonance frequencies can also appear in the frequency contentdue to the violence of the phenomenon.Figure 4 : Final bulk auto-ignition with associated pressure oscillationsThis result shows that we can use not only the same sensor to detect knock and pre-ignition, but also the same kind of methodology for the data analysis and treatment.DESCRIPTION BASED UPON IMAGING Imaging systemNumerous tests were made to find a special operating point with a high frequency of pre-ignitions but always with limited intensities. The selected settings are summarized here below in Table 3 (reference for ignition and injection timings is taken on the combustion TDC). Engine speed (rpm) 1000 IMEP (MPa) ≈ 1.8 T coolant = T oil (°C) 95Spark Advancefrom KL to KL -10 CAD Start of Injection (CAD BTDC) from 220 to 260 CAD Intake temperature (°C) from 30 to 50 Boost pressure (MPa)≈ 0.18Table 3 : Operating point for direct pre-ignition visualisationsA non-intensified colour Charge-Coupled Device (CCD) camera was used to visualise pre-ignition in the combustion chamber (see Table 4). We decided not to use any additional light source relying only upon the light that the combustion would emit itself.TypeIDS uEye UI-2210-M VGA Camera – CCD SensorResolution 640*480 Colour Colour Start timing (CAD)4.5 CAD before Spark Advance (SA)Opening duration (CAD) 9Table 4 : Main characteristics and settings of the cameraThe camera was mounted on an air-cooled endoscope placed on the flywheel side of the cylinder head. The field of view with such an assembly is given in Figure 5. The opening duration and start timing of the camera imply that during a normal combustion only a small brightIntake valvesExhaust valvesSpark plug holeFigure 5 : Field of view in the combustion chamber with spark position indicated by dashed circleImage processingImage processing is relatively involved due to acquisition settings : the light sources are essentially combustion related, leading to extreme contrast conditions (dark and bright areas), combined with a number of non-linear disturbances than should be removed before image enhancement, to avoid noise amplification. Figure 6 displays a detail of an image (top) along with its histogram (bottom) for each red, green and blue colour plane. Colour intensities are scaled between 0 (dark) and 1 (bright) and represented on the horizontal axis, while the colour proportions, between 0 (rare) and 1 (frequent) are represented on the vertical axis with a logarithmic scale. Dark intensities are thus prominent (left end), with a fairly low proportion of intermediate intensities, as indicated by “orders of magnitude” decreases in the central part of the histogram. Let us precise that this image contains a pre-ignition even if it is rather invisible at this time.insight to the non visible parts of the image.The proposed processing method is based on non-linear image denoising and enhancement based on the discrete wavelet transform (we refer to [14] for a detailed exposition on wavelet transforms). The latter constitutes an alternative to the Fourier transform which is better suited to local features (e.g. contours) preservation. It consists in iteratively filtering low and high frequencies of the image rows and columns. The result of this decomposition on two levels is given in Figure 7. The top left sub-image corresponds to a filtered and sub-sampled approximation of the image in Figure 6 (top), while other sub-images contain mid-range and high frequencydetails. This decomposition preserves all the informationsince the sub-images may be recombined by the inversewavelet transform to recover the original image.We observe in Figure 7 (coloured) random noisecomponents in the details, as well as distinct valueslocated around the bright spot location. Moreover theapproximation now exhibits (in light blue) information inits centre part that enhances a potential previouslyinvisible reaction zone. Denoising with wavelettransforms basically consists in cancelling noise relatedcoefficients, while retaining contour information toprevent image over-smoothing, as proposed in [15]. Inthis work, we have used a slightly more efficientdecomposition, called the dual-tree wavelet transform[16], which yields state-of-the-art performance for multi-channel and especially colour image denoising [17].Possible reaction zoneSparkFigure 7 : Two-level wavelet decomposition of theimage in Figure 6ResultsThe main steps of the combustion process during a pre-ignition are presented once again here below withimages directly taken inside the combustion chamber(see Figure 8).Since the camera was triggered at a constant timing, wecould not analyse the development of a single event.What we propose here below is a description basedupon four pre-ignition cycles with different timings andintensities so as to illustrate the main steps of thecombustion.Cylinder pressureRaw images Processed imagesFigure 8 : Examples of pre-ignitions with different timings and intensitiesRegarding the cylinder pressure, cycle n° 636 does not especially bring to light any pre-ignition. But if we take a closer look at the processed image, we can notice that a reaction zone is visible on the exhaust side of the combustion chamber. We assume here that a pre-ignition took place during this cycle but it was so slow that it was caught and masked by the normal combustion initiated at the spark plug.Cylinder pressure of cycle n° 579 clearly shows an occurrence of pre-ignition. Indeed, we can notice a light deviation at the time of the spark which is impossible unless the combustion began earlier. The associated processed image also shows a reaction zone which seems to be located in the background and once again on the exhaust side of the combustion chamber.Cycles n° 546 and 285 reach roughly the same maximal cylinder pressure. However, we can notice that the pressure gradient is slightly higher for cycle n° 285 which seems to be correlated with the stronger intensity on the associated raw image.The final step of bulk auto-ignition is not visible on those four cycles because we made everything to avoid violent pre-ignitions with an early timing. However, some were inevitable and we managed to catch a few as we can see in Figure 9 where the combustion seems to concern a great part of the combustion chamber while the spark isjust starting at that time.Figure 9 : Bulk auto-ignition at the same time as the spark (processed image)A nyway, this final step is less interesting than the previous development of the combustion. Auto-ignition is mainly a result of the early timing of pre-ignition. The earlier the timing is, the more violent the final auto-ignition can be [2].STATISTICAL ASPECTOBSERVATIONSContrary to pre-ignition on hot surfaces, the pre-ignition that we observed is an unpredictable and sporadic phenomenon. On one hand, this kind of pre-ignition rarely appears and then only when the engine is run under heavy load but on the other hand a single occurrence can sometimes be really dangerous for the engine safety. A n example is shown in Figure 10 with cycle-by-cycle maximal cylinder pressure values corresponding to the 300 first cycles of a whole recording of 1000 cycles. A s we can see, the maximal cylinderpressure of the 38thcycle nearly reached 20 MPa.Figure 10 : Cycle-by-cycle maximal cylinder pressure (1000 rpm, IMEP = 2.5 MPa, DI mode, steady state warm operation)Such an extreme maximal cylinder pressure could be disastrous for a normally designed gasoline engine. That is why we propose here to tackle statistically this problem to define new indexes quantifying the frequency and intensity of pre-ignition. That way, it would be possible to quantify the impacts of an engine settings or of an engine technical definition on its sensitivity to pre-ignition. The aim is to avoid extreme pre-ignitions like the violent one shown in Figure 10 by quantifying more precisely all the pre-ignitions occurrences whatever the engine load is. However, the choice of the statistically observed value must be done carefully because it may hide physical effects. Cycle-by-cycle IMEP for example does not only depend on one parameter but on a combination of several parameters during the whole combustion process (in-cylinder charge motion, air-fuel ratio, heat transfers, ignition and injection characteristics, ... etc.). Thus, the characterization of an engine's sensitivity to pre-ignition through a statistical analysis of IMEP may hide some phenomena since a pre-ignition which would start only afew CA D before the spark could obviously look like a normal combustion and would not be necessarily detected through IMEP.Therefore, the most logical and promising method would consist in supervising the first crank angle degrees of combustion, i.e. the ignition phase, through a statistical analysis of 10 % Mass Fraction Burned [2], 5 % MFB or even 1 % MFB angles [8].Once again, it must be kept in mind that the choice of the data sample affects the analysis. For example, the statistical analysis of the initiation phase (10 % MFB angle – SA ) would mask the pre-ignitions' intensities while a direct statistical analysis of the 10 % MFB angle would enable to keep the information of combustion timing within the cycle and then the pre-ignitions' intensities could also be analysed.This kind of deductive reasoning could also be followed with other data than 10 % MFB angle or IMEP. The maximal cylinder pressure analysis for instance could be more easily implemented and would be more suitable to characterize directly the intensity of pre-ignition and its effect on thermomechanical constraints which represent the crucial point for a highly loaded engine. DATA TREATMENTIf we take a closer look at a bigger sample of cycles, we can notice that a whole range of pre-ignitions does exist (see Figure 11 which completes Figure 10 with the full recording of 1000 cycles). It is not a binary phenomenon with either a normal combustion, or a pre-ignition. Consequently, even if it is the easiest solution, it does not seem judicious to define a simple "on/off" criterion to decide if a given cycle corresponds to a normal or an abnormal combustion.Figure 11 : Cycle-by-cycle maximal cylinder pressure corresponding to the full recording and associated probability density function (1000 rpm, IMEP = 2.5 MPa, DI mode, steady state warm operation) A second way to qualify such a sample of cycles would consist in calculating values representative of the stochastic behaviour of the combustion. Mean and standard deviation are classically used to quantify the IMEP instability for example that is why we could first deduce that a basic criterion based upon them could help us to separate normal and abnormal combustions. The fact is those classical statistical indicators are very sensitive to outliers and can be quickly distorted when too many of those outliers occur.For steady state operation, it means that a single occurrence of pre-ignition would be detected but the more pre-ignition there would be, the less efficient this basic criterion might be. For transient tests, the drifting characteristic of combustion would make this kind of criterion unsuitable even for successive normal combustions. It would be even worse if pre-ignitions occurred during this transient operation such as often happens. Classical statistical values would be frankly unusable because outliers would distort the drift.PRE-IGNITION DETECTION ROBUST STATISTICSSince classical statistical indicators turned out to be quite inefficient to accurately detect pre-ignition, a new methodology based upon robust statistics has been used. The main drawback of classical mean and standard deviation for example concern their great sensitivity to outliers. A few outliers in a given data sample are sufficient to significantly affect mean and standard deviation. This phenomenon is illustrated in Figure 12 with an artificial example consisting of 5 values. Four of them are between 20 and 22 and the fifth one is equal to 2. Regarding the global and mean tendency, one would intuitively say that the real mean of this dataset would be around 21. However, the last value strongly affects the mean and standard deviation calculations leading to a real calculated mean around 17. The median which is the simplest and widest used example of robust indicators has also been reported in this figure and we can notice that this statistical indicator is not affected by the outlier (we refer to [19] for more details on robust statistics).Figure 12 : Artificial example illustrating the impact of outliers on mean valueEngine designers frequently use stability criteria based upon classical statistics (combustion stability for example is commonly analysed with the coefficient of variation of IMEP). However, a lot of them often forget that a mean value is representative of a mean physical phenomenon only if each isolated sample is quite well represented by the mean. In our case, a pre-ignition occurrence is clearly brought to light by a reduced initiation phase or by an increased maximal cylinder pressure for instance. Therefore, robust indicators are needed to accurately set the limit between normal combustions and pre-ignitions. The precise determination of this limit is really important and allows a great efficiency in pre-ignition detection either during engine development on test bench or on board. Three examples are discussed here below to illustrate the efficiency of those robust indicators.A first example for steady state operation is given in Figure 13. One thousand cycles were recorded at 1000 rpm and an IMEP of 2.87 MPa and the associated 10 % MFB angles were calculated. Classical mean and standard deviations are shown in the top figure. Outliers occurrences result in a decreased mean and in an increased standard deviation while robust indicators shown in the bottom figure gives a much better characterisation of the main cloud of cycles corresponding to normal combustions (the duration of the initiation phase rangesindicators (1000 rpm, IMEP = 2.87 MPa, SA = 15 CAD ATDC) However, such a great quantity of data is not alwaysavailable and this is why our new indicators were also used on the first twenty cycles of a recording. Thus, a reduced data sample and an on-line detection could be simulated. Our tests on this second example showed that our indicators were insensitive to outliers even in the case of a reduced sample (see Figure 14). This robustness is a great advantage to accurately detect pre-ignitions cycle after cycle.Figure 14 : Simulation of on-line detection based upon robust statistics (1000 rpm, IMEP = 2.4 MPa, SA = 12 CAD ATDC)Data presented in Figure 14 were used for the third example. A quadratic cycle-by-cycle fluctuating drift was applied on those data to simulate a drift of ignition timing. This transformation is not meant to be representative of the real dynamic behaviour during a load transient. The first objective is to show that the robust statistical approach used here allows the following of the 10 % MFB angle tendencies and the detection of pre-ignitions with an accuracy which is far better than with classical statistics (see Figure 15).Figure 15 : Simulation of on-line detection based upon robust statistics during load transient (1000 rpm, IMEP = 2.4 MPa, initial SA = 12 CAD ATDC) From a global point of view, this kind of methodology could be easily widely applicable to control combustion stability whatever the combustion mode is (either for compression ignition or spark-ignition engines) and whatever the fuel is. It is quite a rare tool for engine designers but robust statistics proved that they could sometimes be really more adapted and efficient than classical ones.PRE-IGNITION CHARACTERIZATION MODELLINGIndependently of the detection aspect, a deeper analysis was performed through a statistical modelling of 10 % MFB angle with the same two main long term objectives : the quantification of the occurrence frequency of pre-ignitions during steady state operation and the detection of those abnormal combustions.Dispersion associated with normal combustions (either for spark-ignition or compression ignition modes) are usually represented by a normal distribution. However, this simple well known symmetrical distribution is not always adapted. An example is given in Figure 16 with an experimental distribution of 10 % MFB angles calculated in the case of a classical combustion mode. A normal distribution fitted on the experimental data is compared to an asymmetrical distribution to illustrate the lack of representativeness of the classical approach.Figure 16 : Comparison of distribution fits obtained with a normal distribution and an asymmetrical one (2000 rpm, IMEP = 0.5 MPa, steady state warm stoichiometric operation, minimum 10 % MFB angle shifted to 0)Pre-ignition occurrences modify the experimental distribution shape. A s can be seen in Figure 17, 10 % MFB angles associated with pre-ignitions make bigger the distribution tail on the low values side. On the contrary, the same approach on maximal cylinder pressure for instance would show that pre-ignitions make bigger the distribution tail on the high values side.。
SPIE论文
the regular petroleum products. Kim and Jin demonstrated that the application of THz-TDS for the analysis of petroleum
ENGINE OIL SG 10W-30, SMA engine oil SG 5W-30, SMA engine oil SG 10W-30, SMA engine oil SG 75W-90 have
been studied by the terahertz time-domain spectroscopy (THz-TDS) in the spectral range of 0.6-2.5 THz. Engine oil with
100048, China; dInternational Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, China
ABSTRACT
Engine oil, most of which is extracted from petroleum, consist of complex mixtures of hydrocarbons of molecular
products and organic solvents [17-18].
In this paper, the optical properties and spectroscopy in terms of the engine oil of different kinds were studied by the
The_Analysis_of_Mena_Value_SI_Engine_Models及翻译
No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. 没有出版者事先的书面申请， 本出版物的任何部分不能以任何形式， 在一个电子检索系统或 者其他方面出现。 ISSN 0148-7191 Copyright 1992 Society of Automotive Engineers, Inc. Positions and opinion advanced in this paper are those of the author(s) and not necessarily those of SAE. 在这篇论文中出现的立场或观点是作者的而不一定是 SAE 的。 The author is solely responsible for the content of the paper. 作者是对论文内容唯一负责。 A process is available by which discussions will be printed with the paper if it is published in SAE Transactions. 如果论文是出版在 SAE 会报上的，关于该论文的讨论可以和论文一起出版。 For permission to published this paper in full or in part, connect the SAE Publications Group. 要获得这篇论文的全部或部分内容的许可请联系 SAE 出版组。 Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 300 word abstract of a proposed manuscript to: Secretary,
SAE论文
ABSTRACT
Due to the increasing use of Fatty Acid Methyl Esters (FAME) in diesel fuel blends and the sensitivity of the latest Diesel engine technology (higher pressures and temperatures), a reliable method for predicting the thermal stability of biodiesel fuels is required. A laboratory bench test, called MicroCoking test, which usually qualifies engine oils, has been modified in order to be used for biodiesel blended fuels. Experimental conditions, and especially temperature range, were optimized in order to lead to a sensitive and discriminating method to qualify pure biodiesel fuels and Diesel blends containing FAME. INTRODUCTION New Diesel engine technologies impose more and more severe constraints on Diesel fuels: temperature and pressure increase in the injection system, the use of a fifth injector in the exhaust line for after treatment system regeneration, etc. Moreover, the increase of Fatty Acid Methyl Esters (FAME) ratio in Diesel fuel formulation modifies some of its physical and chemical properties such as its behavior at high temperature. These facts could lead to varnish or lacquer deposits on some engine parts, especially on the fuel pump and injectors. Consequently, new methods for predicting thermal stability of Diesel fuels containing biodiesel could be very relevant. Numerous test procedures have been developed to measure oxidative stability of FAME, pure or in blends: EN14112 Rancimat, EN12205 gums at various temperatures etc. Nevertheless, methods focussing on thermal stability, ie at higher temperatures, are rare and not so obvious. The oxidation stability tests cover temperature operating range from moderate temperatures around 40 up to 120°C, under air or oxygen atmosphere. These conditions can be compared to conditions the fuel can be subjected to from its storage until its route in the injection system. Thermal stability tests, at higher temperatures (>120°C) are more representative of phenomena which take place from the injection system through the combustion chamber, until the exhaust line.
英文 sae 报告范文
英文 sae 报告范文Alright, here's an example of a SAE (Society, Automation, and Engineering) report in an informal and conversational English style, while adhering to the given requirements:The SAE conference was a blast! The energy in the room was electric, and everyone was eager to share their latest research. I was blown away by the advancements in robotics and AI. You know, there was a presentation on self-driving cars that had me totally mesmerized. It's amazing how far we've come.On the social side, the networking events were a hit. I met so many fascinating people from all over the world. We swapped stories about our work, cultures, and even our hobbies. It was like a mini United Nations of engineers! It definitely broadened my perspective.Automation is truly transforming industries. I sawdemonstrations of robots performing tasks that would've taken humans hours to complete. The efficiency gains are incredible. But, I also had a moment of reflection. With all this progress, what does it mean for jobs and the workforce? It's a topic worth discussing further.The engineering community is such a diverse group. Everyone has their own area of expertise, but we all share a common passion for innovation. I was particularly impressed by a student's project on sustainable energy solutions. It was both creative and practical, a perfect blend of theory and application.Overall, the SAE conference was an incredible experience. I learned a lot, met some amazing people, and was inspired by the work being done in our field. I'm already looking forward to next year's event!。
论车身涂装线输送方式与车身产品的匹配
摘要：汽车车身涂装输送方式与车身产品匹配不良，会导致先进输送设备的功能不能充分发挥，甚至导致车身尺寸精度衰减和结构胶脱落等问题。
在车身产品开发和涂装线规划设计时，进行相关匹配性分析验证，可避免问题发生；介绍了典型的输送方式和白车身结构特点，输送方式对车身产品的潜在不利影响，指明了在产品开发和涂装线规划设计阶段需要关注的要点。
关键词：汽车车身涂装输送方式中图分类号：U466文献标识码：BDOI ：10.19710/ki.1003-8817.20190280论车身涂装线输送方式与车身产品的匹配吴涛（中国第一汽车集团有限公司工程与生产物流部，长春130011）作者简介：吴涛（1960—），男，研究员级高级工程师，工学学士、MBA （工商管理硕士），研究方向为汽车涂装技术及汽车制造技术。
1前言车身涂装无论在技术难度上还是在工艺复杂性方面，都可谓汽车及其零部件涂装之最。
随着涂装技术的进步，目前车身涂装已基本可实现全自动化生产。
机械化输送装置（或系统）是实现自动化涂装的核心要件，直接影响涂装生产效率和涂装质量，业界同行在车身涂装线规划设计中，都非常重视输送方式的选择。
传统的全钢白车身设计中，结构件的连接基本都采用焊接工艺，涂装对车身的结构方面影响不大。
因此，以往在涂装线规划设计时，主要关注白车身外形尺寸、质量、涂装面积、装挂点位置及白车身总成表面状态等，对车身结构件的连接、车身强度、刚度、精度等方面关注不多。
随着车身轻量化技术的发展，车身材料、结构件连接方式趋于多样化，车身的结构强度往往要在涂装后才能形成，涂装生产过程中，可能对车身产品造成的直接或间接的不利影响因素已经不容忽视，尤其在前处理和电泳线，输送方式和车身匹配不良，会导致先进输送设备的功能不能充分发挥，有的甚至导致车身变形和结构胶脱落，影响车身精度和结构强度，脱落物也会造成槽液污染等。
根据多年的工作实践，就车身涂装线输送方式与车身产品的匹配性进行必要的分析总结，供业界同仁参考。
SAE-C2009P119
CAE分析在发动机缸体缸盖设计中的应用曾庆强 李凤琴 徐发扬长安汽车股份有限公司汽车工程研究院 【摘要】 缸体㊁缸盖承受着气体力和紧固气缸盖螺栓所造成的机械负荷,同时还由于接触高温燃气而承受很高的热负荷,工作环境恶劣㊂同时,为了保证气缸良好的密封性,不仅气缸垫的加载㊁卸载特性要满足要求,而且缸体㊁缸盖既不能破坏,也不能变形太大㊂为此,缸体㊁缸盖应该有足够的强度㊁刚度,而缸套变形㊁漏气量和机油消耗量等指标密切相关,因此一个全新设计要考虑具有足够的强度㊁刚度㊁密封性,还要考虑缸套变形对漏气量和机油消耗量的影响㊂在设计前期对缸体㊁缸盖进行一体化分析,以评价缸体㊁缸盖的强度㊁刚度,并评价缸垫的密封效果和气缸套变形的影响㊂ 【关键词】 连杆 静力学 疲劳强度 abaqus femfat AVL⁃GlideCAE Analysis Apply in Design for Block and Head of EngineZeng Qingqiang,Li Fengqin,Xu fayangAutomobile Engineering Institute of ChangAn Automobile Co.,Ltd. Abstract:Block and head endure gas force,bolt force and the thermal force for contact with high temperature gas,work environ⁃ment is very hard,in order to insure sealing of head and block,except the gasket behavior should meet demand,the head and block did not distort and destroy,so they should have enough strength and stiffness,we should consider that blow⁃by and oil consumption af⁃fected by line bore distortion severe.so we carry out analysis of head and block compound in order to evaluate the strength and stiffness of head and block,to evaluate the sealing of gasket and for line bore distortion. Key words:conrod static fatigue strength abaqus famfat AVL⁃Glide引 言 缸体㊁缸盖是结构复杂的箱形零件,其上加工有进㊁排气门座孔,气门导管孔,火花塞安装孔,还铸有水套㊁进排气道和燃烧室等,因此结构十分复杂,且要承受不断变化的气体的爆发压力和螺栓预紧力,同时还要承受因温度不断变化引起的热应力的影响,因此进行CAE分析,校核缸盖㊁缸体是否具有足够的强度和刚度是十分重要的㊂ 缸体㊁缸盖承载着缸内气体作用力和惯性力,而作用在燃烧室上的气体作用力为Ρgas=p gΑ(1) 式中,Ρgas是作用在活塞上的气体爆发压力;A为燃烧室的投影面积㊂ 而计算紧固螺栓预紧力是首先根据最大气体爆发压力选取具体的螺栓类型等级,然后根据螺栓的类型等级计算出相应的紧固螺栓预紧力的大小㊂1 缸体㊁缸盖温度场分析1.1 温度场分析模型简述 首先要进行缸体㊁缸盖温度场分析,以用来进行热应力的分析输入㊂ 一般来说,受热零件中任一点的温度T是其位置和时间的函数,即T=T(x,y,z,t),x㊁y㊁z是位置坐标,根据传热学原理,温度函数满足下列微分方程:∂2T∂X2+∂2T∂Y2+∂2T∂Z2=Cρλ∂T∂()t(2) 如果T只随位置改变而不随时间改变,即稳定温度场T=T(x,y,z)函数满足下列微分方程为∂2T∂X2+∂2T∂Y2+∂2T∂Z2=0(3) 计算瞬态热分析需要给定起始条件和边界条件,求解稳定温度场分析只需给定边界条件,起始条件就是起始时刻缸盖㊁缸体的温度场,边界条件就是物体表面与外围介质间的传热关系,共计三类边界条件: 第一类边界条件是已知物体表面的温度㊂ 第二类边界条件是已知通过物体表面的热流通量㊂ 第三类边界条件是已知物体与外围介质间的换热系数和介质温度㊂ 在本次缸体㊁缸盖温度场分析中,分别采用了第二类边界条件和第三类边界条件,其中水套的表面采用了第二类边界条件,而与空气㊁润滑油接触的表面采用第三类边界条件,分析模型见图1㊂1.2 温度场结果分析 从图2燃烧室表面温度分布图可以看到,在排气门与火花塞之间温度最高为248℃,小于材料的最高温度要求260℃,且在进排气门鼻梁区的温度变化趋势可以看到,温度是以近似正弦函数形式平滑上升,没有过度的温度升高和降低(图3),且在燃烧室表面至水套表面的厚度方向上,温度从160℃到240℃平滑过渡(图4)㊂由图5水套表面温度分布图可以看到,水套表面的最高温度为146℃,气泡沸腾图1 有限元分析模型出现在150℃,且在150~160℃之间,气泡沸腾因为表面沸腾气泡的存在加大了壁面边界层的扰动,从而提高了壁面的放热能力,造成了通过缸壁的热流密度增大,壁面的换热系数增大㊂这时带来的是有益的影响,但是水套表面温度大于160℃时,由于壁面附近气泡逐渐连成一体形成一层不动的气膜,气泡沸腾转换为膜态沸腾,反而阻碍了换热能力的加强,因此壁面温度只要小于160℃即可满足要求,从而引起了受热部件局部严重过热,见图5㊂图2 燃烧室表面温度分布图图3 鼻梁区温度变化趋势图图4 鼻梁区温度变化趋势图图5 水套表面温度分布图图6 沸腾换热系数变化趋势2 缸体㊁缸盖热应力分析2.1 应力和疲劳强度分析 为了计算疲劳强度,分别计算装配工况,热机状态下的应力分布以及气体爆发压力作用在不同气缸下的应力㊂利用这几种工况下的应力的变化趋势,分别计算出平均应力和应力幅,最后根据SMITHS 方法计算疲劳安全系数㊂ 从图7~图11中可以看出,在气门导管孔和螺栓孔的倒角附近出现了比较大的应力集中,且为拉应力因此增大圆角半径就很有必要㊂图7 应力计算工况图8 燃烧室背面Von.mise 应力图图9 燃烧室背面Max.principl 应力图图10 水套上表面Von.mise应力图2.2 缸垫密封性分析 缸体㊁缸盖的密封是通过螺栓压紧缸体㊁缸盖之间的缸垫实现的㊂当缸垫的变形补偿了被密封平面的不平度,并在面上产生了足够的压力后,密封就可以保证㊂密封是否可靠与被密封件的刚度和压紧力的大小㊁分布以及密封垫片的材料和结构等因素有关㊂因此密封垫压力的大小,可以用来评价缸体㊁缸盖的刚度㊁螺栓的位置㊁预紧力的大小㊁密封垫的性能是否满足要求㊂从图12~图14可以看出密封压力在18~50MPa之间,满足密封的要求,且最大密封压力不至于压损缸垫㊂2.3 缸套失圆度分析 缸套与活塞组件配合来保证燃烧室的密封㊂温度很高的图11 水套上表面Max.principl应力图图12 缸垫上密封压力图活塞在缸套内高速滑动,如果缸套变形太大,活塞就会在缸套内的摆动较大,从而引起拉缸或者密封性不好等故障㊂因此校核缸套在冷机和热机状态下的失圆度就非常必要,本文分通过两个步骤来校核缸套变形,步骤一:直接法,直接提取缸套的变形(图15㊁图16),并进行傅立叶变换,其二阶幅值小于30μm,三阶幅值小于12μm,四阶幅值小于8μm,五阶幅值小于5μm,如满足进行步骤二,利用AVL⁃GLIDE 建立活塞的动力学模型,对缸套活塞进行接触分析㊁活塞动力学分析㊁润滑油消耗分析㊂2.3.1 缸套径向失圆度及其傅立叶变换 提取缸套的径向变形,并要求冷机缸套除上下两层其余的径向变形最好不要大于20μm,热机缸套变形最好不要大图13 缸垫上水套密封压力趋势图图14 缸垫上燃烧室密封压力趋势图于110μm(图15㊁图16)㊂图15 冷机工况下缸套变形2.3.2 缸套轴向变形及其傅立叶变换 本文只提取了热机状态下的轴向变形,并做了傅立叶变换,并要求其二阶幅值不大于20μm,二阶幅值不大于图16 热机工况下缸套变形12μm,二阶幅值不大于6μm,并把缸套热态变形导入AVL⁃GLIDE 模型就行了接触分析㊁活塞动力学分析,润滑油消耗分析[见2.3.3]㊂图17 热机工况下缸套轴向变形和傅立叶变换图18 活塞动力学分析模型2.3.3 缸套与活塞的接触分析 通过接触分析发现,缸套与活塞的接触压力,在进气行程中活塞对缸套次推力面有个轻微的冲击,因为持续时间较短,可忽略其影响(图18)㊂通过计算其漏气量单缸为5.173L/min,整机为20.692L/min,满足国家标准23.4L/min㊂图19 缸套与活塞接触状态图20 窜气量3 试验验证分析 通过设计一个缸盖的应变试验,来进一步验证分析模型的正确性㊂ 试验分成两个步骤㊂首先预紧螺栓,并记录应变片的测试结果(图21),该测试结果与分析结果非常吻合(图22)㊂然后在发动机运转过程中,记录应变片的测试结果,并剔出螺栓预紧力㊁热应力的影响,再与计算分析的数值作比较(图23),发现分析结果与试验结果非常接近㊂由此验证了分析模型的正确性㊂图21 应变片测试位置图22 应变片测试位置图23 应变片测试位置4 结论 发动机的缸体㊁缸盖承受着交变的气体爆发压力㊁热应力㊁机械应力,并且工作环境异常恶劣,且其模具昂贵,所以在开发过程中,期望在初期就能暴露设计中的问题,以免以后模具改动,增加成本㊂而CAE技术可以在没有样机的情况下,验证设计模型的性能,尽早暴露问题,避免了模具的后期改动,甚至报废,节约了成本㊂参考文献[1] 陆际清,等.汽车发动机设计(第二册)[M].北京:清华大学出版社,1992.[2] 曾庆强,等.ABAQUS在发动机缸盖失效解析中的应用[C].ABAQUS年会论文,2008.。
(完整版)汽车制动系统毕业设计论文
优秀论文审核通过未经允许切勿外传摘要Formula SAE比赛由美国车辆工程师学会（SAE）于1979年创立，每年在世界各地有600余支大学车队参加各个分站赛，2011年将在中国举办第一届中国大学生方程式赛车，本设计将针对中国赛程规定进行设计。
本说明书主要介绍了大学生方程式赛车制动的设计，首先介绍了汽车制动系统的设计意义、研究现状以及设计目标。
然后对制动系统进行方案论证分析与选择，主要包括制动器形式方案分析、制动驱动机构的机构形式选择、液压分路系统的形式选择和液压制动主缸的设计方案，最后确定方案采用简单人力液压制动双回路前后盘式制动器。
除此之外，还根据已知的汽车相关参数，通过计算得到了制动器主要参数、前后制动力矩分配系数、制动力矩和制动力以及液压制动驱动机构相关参数。
最后对制动性能进行了详细分析。
关键字：制动、盘式制动器、液压AbstractFormula SAE race was founded in 1979 by the American cars institute of Engineers every year more than 600 teams participate in various races around the world,China will will be for design of the provisions of the Chinese calendar.This paper mainly introduces the design of breaking system of the Formula Student.First of all,breaking system's development,structure and category are shown,and according to the structures,virtues and weakness of drum brake and disc brake analysis is done. At last, the plan adopting components braking and channel settings and the analysis of brake performance.Key words:braking,braking disc,)的汽车上。
SAE-C2009E135轿车R&H 性能仿真结果的分析评估研究
图摇 2 图摇 3
551
图摇 5 图摇 6 图摇 7 图摇 8
图摇 4
图摇 9
552
SAE鄄C2009E135
2009 中国汽车工程学会年会论文集摇
1郾 2摇 悬架及转向装置的仿真分析后处理
摇 摇 ADAMS / PostProcessor 可以向用户直接提供绝大部分仿 真结果并绘制其相应曲线, 对于少数要求的结果, 比如最小 转弯半径, 需要通过相应的计算公式得出, 可以借助相关数 学工具( MATLAB 等) 进行编程或者使用 EXCEL 编写计算文 件, 从而使得重复工作量大为减少, 也为以后相类似的仿真 结果分析提供额外的快捷工具。
2摇 针对前后悬架 R&H 性能仿真结果及其分 析评估
图摇 10
2郾 1摇 性能依据
摇 摇 在设计阶段, 通过借鉴以往车辆的设计理论与试验结 果, 把底盘 R&H 领域的各个参 数 尽 量 控 制 在 表 1 的 范 围 之内。
2郾 2摇 前悬架运动学仿真结果及其分析评估
图摇 11
2郾 2郾 1摇 四轮定位参数( 空车状态)
每车轮
5
主销内倾角( 毅 )
7 ~ 16
6
车轴偏距 / mm
30 ~ 70
位于轮心
7
主销偏距 / mm
FF
普通车辆 FR
( -)0 ~ ( -)12 10 ~ 30
8
阻尼系数( c / Cc)
亚太 & 美国 欧洲
0郾 2 ~ 0郾 4 0郾 3 ~ 0郾 5
参摇 摇 数 主销后倾角( 毅 ) 车轮外倾角( 毅 ) 车轮前束角( 毅 ) 主销内倾角( 毅 ) 主销后倾拖距 / mm 主销偏距 / mm
汽车方面的毕业论文范文
汽车方面的毕业论文题目：智能汽车自动驾驶系统的安全性分析摘要随着人工智能和物联网技术的飞速发展，智能汽车自动驾驶系统正逐步成为未来交通的核心技术。
本文全面分析了智能汽车自动驾驶系统的安全性问题，揭示了传感器故障、算法缺陷、通信中断及定位误差等关键挑战。
针对这些问题，本文提出了一系列提升策略与技术，包括采用高可靠性和高精度的传感器技术、优化算法模型和人工智能技术、增强通信技术的安全性和稳定性以及提升定位精度等。
通过文献综述、理论分析和实验验证，本文证实了这些策略与技术在提高智能汽车自动驾驶系统安全性方面的有效性。
实验结果显示，优化后的传感器和定位技术显著提升了系统对环境信息的感知和定位精度，而先进的算法模型和通信技术则增强了系统的决策和通信稳定性。
然而，自动驾驶技术的复杂性和不确定性仍需持续关注，未来研究应聚焦于传感器技术、算法模型、通信技术以及评估体系的进一步优化和创新。
关键词：智能汽车自动驾驶系统；安全性分析；传感器技术；算法模型；通信技术；定位技术；实验验证目录摘要 (1)第一章引言 (3)1.1 研究背景与意义 (3)1.2 国内外研究现状 (4)1.3 研究内容与方法 (5)第二章智能汽车自动驾驶系统概述 (7)2.1 系统基本原理 (7)2.2 系统组成部分 (7)2.3 系统主要功能 (8)第三章智能汽车自动驾驶系统安全性问题 (10)3.1 系统安全性问题分析 (10)3.2 安全性问题产生原因 (11)第四章安全性提升策略与技术 (13)4.1 提升策略 (13)4.2 关键技术 (14)第五章实验与分析 (15)5.1 实验设计 (15)5.2 实验结果 (16)5.3 结果分析 (17)第六章结论与展望 (18)6.1 研究结论 (18)6.2 研究展望 (19)第一章引言1.1 研究背景与意义随着科技的日新月异，人工智能和物联网技术已全方位地融入我们的生活，尤其智能汽车自动驾驶系统更是现阶段汽车行业的研究焦点。
SAE汽车防腐蚀老化分会年会论文模板
收稿日期：2015-03-21；修订日期：2015-04-15基金项目: ”十二五”科技支撑计划项目(2011BAK10B05, 2012BAD29B05)；质监总局公益项目(2011IK260)作者简介:XXX （1991—）,男，上海人，硕士研究生，主要研究方向为表面工程。
通讯作者：XXX （1965—）,男，北京人，博士，教授, 主要研究方向为再制造工程。
注：第一作者为学生的必须介绍通讯作者。
SiO 2对镁合金阴极电泳涂层耐磨性的影响XXX 1，XXX 2，XXX 2（1.上海交通大学，上海 200240；2. 北京科技大学，北京 100083）摘 要：摘要主要由三部分组成，即：研究的问题、过程（或方法）、结果。
关键词：镁合金；阴极电泳涂层；耐磨性；磨损机制在常用金属结构材料中，镁合金的耐蚀性较差，常需进行耐蚀防护处理，如有机涂层、微弧氧化和稀土转化膜[1-3]等，其中最常用的是有机涂层防护处理。
该方法具有操作简便、成本低、环保、涂层耐蚀性强等优点[4]，但涂层耐磨性较差，在使用过程中，镁合金部件与其他物品发生摩擦、磕碰，都会对有机涂层造成损伤，这既影响了美观，也影响了膜层的防护性能。
1 试验1.1 涂层制备所用变形镁合金AZ31B 的化学成分（以质量分数计）为：Si 0.021%，Fe 0.0015%，Cu 0.0011%，Mn 0.4%，Al 2.91%，Zn 0.85%，Ni 0.00084%，Mg 余量。
镁合金的前处理流程为：60 ℃洗衣粉溶液中浸泡40 min →水清洗干净→砂纸打磨至2000号→酒精中洗净→晾干备用。
1.2 性能测试及组织观察1）采用UMT 摩擦磨损测试系统测试四种涂层的耐磨性能。
取完整样品，在中间沿宽度方向以直线往复式进行摩擦磨损测试，相关测试参数如下：滚球为直径2 mm 的GCr15钢，摩擦速度15 mm/s ，载荷5 N ，测试时间10 min 。
用蔡司EVO18扫描电镜、数码相机、奥林巴斯BX53光学显微镜对涂层及其摩擦磨损后的磨痕进行观察，并用扫描电镜附带的EDS 能谱仪分析元素和成分。
SAE下载论文
SAE TECHNICALPAPER SERIES2008-01-1537An Optimization Design of Throttle Body forEFI Motorcycle EnginePeng Han-rui, Peng Mei-chun, Zheng Lin-li,Deng Xu-bing and lin Yi-qingGuangdong University of T echnologyXie Xing-wenGuangzhou City Panyu Huanan Motocycle Enterprise Group Co., Ltd.2008 SAE International Powertrains,Fuels and Lubricants CongressShanghai, ChinaJune 23-25, 2008By mandate of the Engineering Meetings Board, this paper has been approved for SAE publication upon completion of a peer review process by a minimum of three (3) industry experts under the supervision of the session organizer.All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.For permission and licensing requests contact:SAE Permissions400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: permissions@Tel: 724-772-4028Fax: 724-776-3036For multiple print copies contact:SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-0790Email: CustomerService@ISSN 0148-7191Copyright © 2008 SAE InternationalPositions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is published in SAE Transactions.Persons wishing to submit papers to be considered for presentation or publication by SAE should send the manuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USA2008-01-1537 An Optimization Design of Throttle Body for EFIMotorcycle Engine Peng Han-rui, Peng Mei-chun and Zheng Lin-li, Deng Xu-bing and lin Yi-qingGuangdong University of TechnologyXie Xing-wenGuangzhou City Panyu Huanan Motocycle Enterprise Group Co., Ltd. Copyright © 2008 SAE InternationalABSTRACTThis paper studied the optimization design of throttle body for electronic control motorcycle engine FY156FMI. It was studied the influence of the inner diameter, configuration of valve and its axis and inner configuration of the pipe of throttle body on the engine performance. The inner diameter of throttle body was designed on the basis of resonance theory. And the prototypes of throttle body designed were manufactured and tested by engine experiment. Results showed that the power of the engine applied with the throttle body, which has been optimization designed with a thinner throttle valve and a taper inlet port, and the size of inner diameter of throttle body increased from 26mm to 28mm and the thickness of the axis decreased, was improved effectively.The optimization throttle body can meet the design target.INTRODUCTIONAir flow has an important influence on the efficiency of engine intake charge, and the engine power and consumption directly. More fresh air could be taken, more fuel could be injected into engine in the same intake condition and same volume of cylinders, then the effective power of engine will be more high with the similar combustion [ 1 ].The intake process is complex and resonant, and it has a connection with the configuration of intake pipe directly. The intake resistance will increase with the diameter reduced and length of the intake pipe increased. And the peak of intake charge coefficient will move to the low velocity [ 2 ]. For this reason, scholars have paid much attention to the configuration of the intake pipe and the dynamic characteristic of the intake flow [3-6] . As a part of the EFI engine intake pipe, the configuration of throttle body has a great influence on the power, torque and fuel consumption of engine.This research was based on a gasoline engine 156FMI for CG125 motorcycle which is a carburetor engine originally. When the engine was changed to EFI engine, it was required to design a throttle body. The target of throttle body design is to ensure that the maximum power of the EFI engine is not lower than the original carburetor engine.INITIAL DESIGN OF THTOTTLE BODYThe throttle body of EFI engine is substitute for the carburetor. Therefore the overall externaldimensions of throttle body are equal to the carburetor. The length of throttle body should be consistent with the carburetor to avoid the modification of vehicle frame and other parts. The design project of throttle body is integrated, namely, the throttle body, throttle positionsensor, manifold pressure sensor and inlet temperature sensor are integrated together .The components structure of integrated throttle body for this research is shown in figure 1. The integrated structure has the advantage of lowcost, good reliability , and easy to install etc..Figure 1 Configuration of the integrated throttle bodyFigure 2 Configuration of the initial design throttle bodyThe inner diameter of carburetor for the original motorcycle engine is ∅26, therefore, inner pipe diameter of throttle body for EFI engine was designed to ∅26 too. The configuration of inlet pipe of throttle body is shown in figure 2.In order to confirm that the throttle body meets the design target of power and fuel consumption. The engine performance was tested on engine test bench. The engine performance was conducted at different speed points, which is properly distributed in speedrange with full throttle open. Usually, more than eight measurement points would be adopted.The Major Specifications of original carburetor engines were shown in table 1. The test equipments included MZDC-22 eddy current dynamometer, MCS-960 fuel consumption meter, which were made in Zhong Cheng Equipment Co., Ltd.Table 1 Major Specifications of prototype engine with carburetor Engine Type FY156FMIFormatsingle cylinder, four stroke, natural aircoolingCylinder Diameter（mm） 56.5Stroke（mm） 49.5 Displacement（mL） 124Compression Ratio 9.0:1Max Power（kW）/ Speed（r/min） 8.1/8500Power Rating（kW）/Speed（r/min） 7.2/8000Max Torque（N.m）/Speed（r/min） 9.35 /8000Min Specific FuelConsumption（g/kW.h）≤365Engine performance comparison was conducted between EFI engine with a ∅26 throttle body and original carburetor engine FY156FMI. The results were shown in figure 3. From the figure 3, it can be seen that the power of the EFI engine with a ∅26 throttle body is lower than that of the original carburetor engine distinctly. So it can’t meet the design target. There are two reasons for the power dropping of EFI engine:•The size of inner diameter of throttle body may be too small.•The configuration of throttle body is unreasonable, There are two stairs inthe inlet port of intake pipe of thethrottle body (as shown in figure 2 ),which causes the air flow resistance.The intake charge of engine isinsufficient and causes the enginepower dropping. Therefore it isimportant to improve the throttle body,Figure 3 Comparison of Full load performances of EFI engine with a ∅26 throttlebody with carburetor engineIMPROVEMENT DESIGN OF THE THROTTLE BODYAfter the basic configuration of throttle body had been set, it is important to improve the design of length, the inner diameter of the throttle body and the internal structure according to the design requirement and the engine technology parameters.The resonance theory was applied to the design of length and the diameter of throttle body. If the frequency of intake system and the cycle of charge are harmonious under specific velocity of engine, it will cause the high wave of pressure in the intake pipe before the intake valve closed, make the pressure in the intake pipe augmented, and increase the engine intake charge. The effect is called resonance theory. The advantage of the resonance intake system is that it can work reliably to increase the intake charge without any moving parts, thereby increase the engine power and the torque with lower cost under specific velocity. The technology parameters of FY156FMI engine show that the velocity at maximum torque is 8000r/min, therefore the research took this velocity to carry on the design of resonant intake pipe to increase the maximum power and the torque of the engine. Because of the length of the throttle body should be consistent with that of carburetor, only the internal pipe diameter design is need.THE DESIGN IMPROVEMENT OF INNNER DIAMETER OF THROTTLE BODYStrictly, the inner diameter of resonant pipe should be designed according to the pipeline friction and the undulation effect. In view of the friction effect, the pressure dropped in the pipeline is proportional to the countdown offourth power of the inner diameter, thus, larger diameter should be adopted. But in other view of pressure undulation effect, smaller diameter should be adopted to increase the pressure undulation amplitude. Just considering the impact of friction, Kastner pointed out thesmallest diameter estimation formula as following:mm n s d d i 51624min107.12)(⎦⎤⎢⎣⎡×=[7] （1） “d” represents the diameter of cylinder, “s” represents the piston stroke, “ n” represents the rotation speed of engine.Put “d =56.5mm, S =49.5mm, n =8000r/min” into the formula （1）to calculate the smallestdiameter. The result is min )(i d =27.5mm, rounds to d i ＝28mm. And the two staris in the inlet port of the throttle body is removed. The inner configuration of intake pipe designed isshown in figure 4.Figure 4 Throttle body with ∅28 intake pipe OPTIMIZED DESIGN OF THE VALVE AND AXIS OF THROTTLE BODYIn order to reduce the flow resistance, the optimized design of valve and axis of throttle body can refer to the design of choke valve. One option is that the half of axis was cut. The axis is semicircle. Another option is that both sides of axis are beveled. The axis is flat. The two options are contributed to reduce the effect of flow resistance. Also, the thickness of the valve and the size of the axis diameter decreased in optimized design.There is a stair at the inlet port of throttle body in the initial design option. For improving, the side of the pipeline where the valve body connected with the air filter was expanded into a certain degree of taper, to smooth the transition and reduce the air resistance further. Design options of throttle bodies are shown in figure 5.The samples of throttle body design were manufactured and tested by engine experiment to choose the best one. The state of initial design and improvement design options of throttle body are shown in table 2.Table 2 Throttle body design optionsFigure 5 Valve and axis optimization design options of throttle bodyENGINE PERFORMANCE COMPARISON TEST AND DATA ANALYSISFour kinds of throttle bodies, as shown in table 2, were applied to a same FY156FMI EFI engine, and it was tested their effect on performance of engine. The test equipments are the same as above.It is showed the power curves in full load for FY156FMI EFI engine applied with differentthrottle bodies in figure 6. The analysis and results are listed as following:•The engine power improved effectively when the diameter of throttle bodyincreases from 26mm (option 0)to28mm (operation 1, 2, 3), and thegreatest increment is 1.29kW.•The power of EFI engine equipped with only enlarging inner diameter throttlebody(option 1) is lower than that ofcarburetor engine. But the power of EFIengine almost is equal to that ofcarburetor engine, when EFI enginewas equipped with the throttle body witha thin valve and a taper inlet port, andthe size of inner diameter increasedfrom 26mm to 28mm and the thicknessof the axis decreased (option 2 andoption 3)，also, the maximal power is alittle larger than the carburetor engine’s.•When the thickness of valve and axis decreased(option 2 and option 3 ), theengine power is increased by 0.2 ～0.3kW. And there are not obviousdifferences of the influence on powerbetween the semicircle axis and the flataxis.Figure 7 shows specific fuel consumption curves of option 2(semicircle axis) and option 3 (flat axis)that EFI engine equipped with throttle body and original carburetor engine. Obviously, after enlarging throttle body inner diameter and decreasing the thickness of the valve and axis, EFI engine specific fuel consumption is distinctly lower than that of the carburetor engine. The specific fuel consumption reduced by 5.8% averagely. Moreover, the specific fuel consumption of the EFI engine equipped with the semicircle axis had only a few fluctuations at the entire test speed scope, especially at the middle and high speed, the specific fuel consumption is almostthe same.Figure 6 Performance of full load of engineFigure 7 Specific fuel consumption comparisonCONCLUSIONSIt can be concluded from the above analysis that the throttle body has a great influence on the EFI engine power and fuel consumption. The paper applied the optimization design, such as increasing inner diameter from 26mm to 28mm, decreasing the thickness of the valve and the axis and smoothing the inside of intake pipe to increase the engine power. The results showed that the power of EFI engine equipped with the optimization design throttle body is almost equal to the carburetor engine. The optimization throttle body can meet the design target. Specially, the fuel consumption of EFI engine equipped with semicircle axis type throttle body is much lower than that of carburetor engine.REFERENCES[1] Yu Guohe, Yan Xiang’an. “Experimental Study on Influence of Inlet Pipe on Dynamic Performance of Single-cylinder Engine”. China Mechanical Engineering, 2006(17) supplement:140-143[2] Zhou Longbao. “Internal-combustion Engine”. Beijing: Machinery Industry Press,1999 [3] Wilson N, Watkins A, Dopson C. “A symmetric valve strategies and their effect on combustion” .SAE Paper 930821.1993[4] Feng Mingzhi, Liu Shuliang. “Experimental Study on In-cylinder Air Flow in Four-valve Spark Ignition Engine”. Journal of Tianjin University. 2000(3):355-359.[5] Pei Pucheng,Liu Shuliang, Fan Yongjian. “An investigation on the tumbling intake ports configuration for multi valve S.I. engine”. Journal of Internal CombustionEngine,1993,47:13-19[6] Zhang huiming, Hong Jiadi. “Studyon the inlet system of improved diesel engine”.Small Internal Combustion Engine,1998(6): 28 - 31. [7]Xiao Min, Zhang Qingsong. “Calculation and Design f or JL368 Q Petrol Engine Intake System”. Journal of China Shipbuilding Institute, 2002,16(1):56-61。
汽车试验学论文
《汽车试验学》课程论文题目车轮性能实验学院工程技术学院专业车辆工程年级 2 0 1 2 级学号222012322220091姓名黄林波成绩2015年6月15日车轮性能试验黄林波车辆一班、222012322220091试验目的近年来，随着汽车技术水平的提高，汽车车轮对汽车的行驶安全性和操纵稳定性的影响日益受到人们的关注。
鉴于此，SAE、JASO以及ISO等标准和我国标准均对汽车车轮做出了详细的技术要求，其中动态弯曲疲劳试验、动态径向疲劳试验、冲击试验是汽车车轮最基本、最主要的性能试验。
我国汽车车轮的性能试验主要参照一下3个标准进行，即GB/T 5334－2005 《乘用车车轮性能要求和试验方法》、GB/T 5909－2009 《商用车辆车轮性能要求和试验方法》，以及GB/T 15704－2012《道路车辆轻合金车轮冲击试验方法》。
1、动态弯曲疲劳试验1.1试验方法车轮动态弯曲疲劳试验也称动态横向疲劳试验，该试验是使车轮承受一个旋转的弯矩，模拟车轮在行车中承受弯矩负荷。
试验弯矩M为强化了的实车中承受的弯矩，可表达为M=（μR+d）FvS式中，M为弯矩（N﹒m）；μ为轮胎与路面间的设定摩擦系数；R为轮胎静负荷半径，是汽车制造厂或车轮厂规定的用在该车轮上的最大轮胎静半径（m）；d为车轮内偏距或外偏距（m）（内偏距为正值，外偏距为负值）；Fv为车轮或汽车制造厂规定的车轮上的最大垂直静负荷或车轮的额定负荷（N）；S为强化试验系数。
图1 车轮动态弯曲疲劳试验机结构示意图试验在图1所示的专用试验机上进行。
试件为一全新车轮。
试验时，按图将车轮（或车轮轮辋）牢固地夹紧在试验夹具上。
试验装置的连接面应与被试车轮用在车辆上的车轮安装装置相当。
试验连接件安装面和车轮安装面均应光洁、平整。
加载臂和连接件用无润滑的双头螺栓和螺母（或螺栓）连接到车轮的安装平面上，安装情况应与装于车辆上的实际使用工况相当。
在试验开始时，把车轮螺母（或螺栓）拧紧至汽车制造厂所规定的力矩值。
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方程式赛车防撞系统毕业论文答辩课件
传感器由铝盘、光电 晶体管、红外光电二 极管、过孔及外壳支 架等部件组成一体。
测速
液晶显示
断油控制与报警系统
四、整机原理图
超声波 传感器
信号处理电路
速度信息 LCD 状
MCU 障碍物信息 控制系统
状态信息
态 显 示
测速 传感器
信号提取电路
电
报警信息 路
五、被动安全—蜂窝铝的使用
台车碰撞试验结果表 明: 蜂窝铝芯碰撞吸 能器能在赛车碰撞时， 发生褶皱变形，从而 吸收大量的碰撞动能。 XMUT2010方程式赛 车吸能器满足赛事规 则要求。
六、实现功能
1、在测速方面能准确反映赛车时速。
2、在测距方面能准确反映赛车前障碍物的距离。
3、在断油控制与报警系统方面能适时报警并切断喷油器供油线路使喷油 器停止工作。
4.在显示器上能准确反映车速、车距。
七、存在不足
1、由于超声波传感器测量距离的局限性不能测量较远距离，在下一 步的设计中应更换测量距离更远的传感器。
大学生SAE方程式赛车 防撞系统研究
一、课题介绍
中国大学生方程式汽车大赛（简称“中国FSAE”）是一项由高等院校汽 车工程或汽车相关专业在校学生组队参加的汽车设计与制造比赛。各 参赛车队按照赛事规则和赛车制造标准, 在一年的时间内自行设计和 制造出一辆在加速、制动、操控性及燃油经济性等方面具有优异表现 的小型单人座赛车, 能够成功完成全部或部分赛事环节的比赛。
本系统是以一种集光、机、电等手段于一体的大学生方程式赛车智 能防撞安全保护系统。
测距
超声波传感器 测距的公式表示为: L=C×T式中L为测量的距离长度；C为超声波在
空气中的传播速度；T为测量距离传播的时间差（T 为发射到接收时 间数值的一半）。发射 Nhomakorabea路被
丰田在SAE会议论文
丰田在SAE会议论文丰田SAE燃料电池快速冷启动的基本思路是，利用燃料电池的浓差过电势拉低燃料电池对外输出效率，将尽可能多的化学能转化为热能用于燃料电池堆本体加热，利用冷却系统小循环均衡燃料电池堆的单片表面温度差异和单片间温度差异。
浓差过电势本意是指，燃料电池电化学反应不断消耗氧气，导致燃料电池空气系统实际供给氧气分压力(等效于浓度)与阴极催化剂层内氧气分压力不同，氧气分压力差值表现为气体扩散层内的压力梯度、促进氧气朝着催化剂层扩散，催化剂层内氧气分压力越低则氧气还原反应的活化过电势越高，结合活化过电势升高与氧气分压力差异，从而量化为浓差过电势。
结合燃料电池电压公式，通过提高浓度过电势而使燃料电池输出电压降低并提高内部发热量，是最为有效的一种方式：理论可逆电势是固定的，活化极化与温度相关而温度是环境与系统共同决定的，欧姆极化与水含量和温度相关而水含量必须精确控制以抑制结冰，浓差极化与空气过量系数和空气压力相关且是灵活可调的。
丰田给出了一组极化曲线，以描述不同温度下(注：过量空气系数、过量氢气系数、空气压力和氢气压力未知)，燃料电池输出电压与电流的关系，并将此极化曲线作为后续系统控制的参照。
随后，丰田给出了一张图，用于描述不同电流下(注：温度未给出)，浓差过电势与过量空气系数间的量化关系，请注意：总体上(大面积单片会有差异)，相丰田给出了一组极化曲线，以描述不同温度下(注：过量空气系数、过量氢气系数、空气压力和氢气压力未知)，燃料电池输出电压与电流的关系，并将此极化曲线作为后续系统控制的参照。
随后，丰田给出了一张图，用于描述不同电流下(注：温度未给出)，浓差过电势与过量空气系数间的量化关系，请注意：总体上(大面积单片会有差异)，相同过量空气系数时，电流越高、浓差过电势越高。
为了简化控制过程(与电流无关)，相同过量空气系数时，将最低浓差过电势作为浓差过电势控制器的最小允许值，即冷启动过程中浓差过电势必须高于此数值。
sae报告
sae报告SAE报告（700字）SAE（Supervised Agricultural Experience）是美国农业教育计划中重要的一部分，它帮助学生在农业领域获取实践和实际工作经验。
在过去的一年中，我参与了SAE计划并完成了一项养殖业务。
我决定在家养了一群鸡作为我的SAE项目。
我开始时购买了20只鸡蛋，并将它们放到育雏箱中进行孵化。
经过21天的孵化，成功孵化出16只小鸡。
我将这16只小鸡转移到了鸡舍中。
在开始养鸡之前，我进行了充分的研究和准备。
我学习了鸡的品种、饲养和疾病预防知识，以确保我能够正确照顾它们。
我建立了一个合适的鸡舍，确保鸡舍有足够的空间和通风。
我还购买了高质量的饲料和饮水器，以保证鸡获得充足的营养和水分。
在养鸡的过程中，我每天都要给鸡换水和饲料，定期清理鸡舍，确保鸡的生活环境干净卫生。
我还要观察鸡的行为和健康状况，及时发现并处理任何疾病或异常情况。
随着时间的推移，我的鸡群逐渐长大并开始下蛋。
我每天能够收集到7到10个鸡蛋。
我将这些鸡蛋收集起来，并在当地市场上销售。
通过销售鸡蛋，我不仅获得了一定的利润，还锻炼了自己的销售和客户服务能力。
通过参与SAE计划，我学到了很多关于养殖业务的知识和技能。
我学会了如何管理一群鸡，从孵蛋开始到鸡蛋的销售。
通过与鸡互动，我也培养了责任心和耐心。
我意识到在农业领域中，需要经过大量的努力和付出才能取得成功。
然而，我也遇到了一些挑战。
在最初几个月，我发现有些小鸡生病并死亡。
我利用我的研究和咨询专家的经验来解决这个问题，并采取了预防措施，确保其他小鸡的健康。
总之，通过参与SAE计划，我获得了宝贵的养殖业务经验，并培养了自己的领导能力和决策能力。
我相信这些经验将对我的未来学业和职业发展产生积极的影响。
我也将继续扩大我的养殖业务，并不断努力提高自己在农业领域的知识和技能。
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AbstractAluminum metal matrix composite brake rotors with a selective ceramic function reinforcement gradient (FRG) have been developed for automotive applications. This paper will highlight the design, manufacturing, and testing of the rotors. Weight saving of an aluminum composite rotor in comparison to an industry standard cast iron rotor is 50-60%. With this material change comes design considerations to manage rotor temperature, rotor surface integrity, and friction. Manufacturing methods to meet these design constraints were needed to develop a viable high performance aluminum composite rotor. High pressure squeeze casting with soluble coring techniques were developed to incorporate the selective FRG MMC rotors. Dynamometer testing was performed, concentrating on brake friction and temperature to evaluate the macro and micro interfaces in the rotors. The rotors’ testing results indicate that a functional reinforced aluminum metal matrix composite rotor is viable option for front and rear brake applications in the automotive and commercial trucking market.IntroductionThe automotive industry has had an emphasis on light weighting, due to factors like NHTSA standards [1] and consumer pressure. Brake rotors are a component that may not see the same emphasis as others, due to the passenger safety requirement of a braking system or cost differential.Metal matrix composites (MMC) are made of nonmetal materials dispersed in a metal matrix. Aluminum MMC’s have and are being used in components like pistons, cylinders, and brake disks. Aluminum MMC’s can be stir-cast to give increased strength, stiffness, thermal resistance and stability over aluminum.REL Inc. and others [2] have directed efforts towards development of an aluminum MMC automotive rotor. A one piece internally vented rotor was the goal of REL’s efforts. This would allow for a lightweight rotor that would have the ability to reduce its temperature faster than a standard rotor. This is crucial for an aluminum MMC rotor to operate under heavy braking conditions. Standard iron rotors have the ability to operate at higher temperatures than an aluminum MMC rotor due to material differences. To compensate, a venting structure is needed to increase airflow and reduce running temperature.Rotor DevelopmentREL’s aluminum MMC material has a high ceramic content. A 50% ceramic volume fraction MMC is achievable. This MMC material has a coefficient of thermal expansion of about half of aluminum. The MMC’s thermal diffusivity is also about half of aluminum’s.In the path to developing an aluminum MMC one piece internally vented automotive rotor, there were three stages of development before the final prototype. This stages are as follows: Single blademotorcycle rotor, solid one piece rotor, and three piece vented rotor. Figure 1. REL aluminum MMC motorcycle rotor and carrierDevelopment of Aluminum Composite Automotive Brake Rotors2016-01-1937Published 09/18/2016 Taylor Erva, Adam Loukus, and Luke LuskinREL, Inc.CITATION: Erva, T., Loukus, A., and Luskin, L., "Development of Aluminum Composite Automotive Brake Rotors," SAE Technical Paper 2016-01-1937, 2016, doi:10.4271/2016-01-1937.Copyright © 2016 SAE InternationalThe single blade motorcycle rotors are for use by road motorcycles. They are generally thin (≈6mm) and have no center section. The entire blade is composed of aluminum MMC with a function gradient. The rotors are being sold as OE replacements for select street motorcycles.The solid one piece automotive rotor is a single blade rotor with a center hub section that has mounting for an automobile. The rotor is selectively reinforced, with the aluminum MMC section being the friction ring of the rotor. The rotor has external vanes, to help regulatetemperature. The hub and venting section are made of aluminum alloy.Figure 2. REL solid one-piece aluminum MMC automotive rotorThree piece vented automotive rotor is similar to the design of the one piece internally vented automotive rotor. It consists of a center hub section and two rotor blade halves. Each rotor blade half holds half of the internal venting structure. The halves are bolted together and then to the hub. The rotor blade halves and venting sections arealuminum MMC. The hub is made of aluminum alloy.Figure 3. REL vented three-piece aluminum MMC automotive rotorOne Piece Vented Automotive RotorThe automotive rotor has these features: Aluminum with selectively reinforced aluminum MMC sections, one-piece construction, andinternal venting.Figure 4. REL vented one-piece aluminum MMC automotive rotorThe rotor is made up of aluminum alloy and aluminum metal matrix composite material. The ceramic reinforced sections of the rotor are the two braking surfaces. The rotor hub and venting sections are made up of aluminum alloy. The MMC braking surfaces have a function reinforcement gradient (FRG). The ceramic density isradially variable, with an increase in volume fraction from the interior to the perimeter of the preform. This radial change in ceramic volume fraction compensates for the increase in energy and stress on the outer section of the rotor during braking.A computational simulation was done to determine the thermal mechanical performance of a rotor during a stop. Results from the simulation show a difference in stress from the outer edge of the rotor to the inner edge. The pattern of higher stress on the outer edge of the rotor to lower stress on the inner edge of the rotor is followed in a simulation with 0% ceramic content and simulation with 100%ceramic content.Figure 5. Stress simulation with 0% ceramic contentFigure 6. Stress simulation with 100% ceramic contentFigure 7. Stress simulation: rotor edge comparisonTensile testing of aluminum MMC samples was done. Samples of specific ceramic volume fractions were tensile tested and Poisson’s ratio was determined from the results. A trend of decreasing Poisson’s ratio as ceramic volume fraction increases can be observed from the results. With this trend, a gradient of ceramic in the metal matrix composite section of the rotor is used to maintain a rotors integrity during a braking cycle. Higher stress regions have higher ceramic content than lower stress regions of the MMC braking surface.Table 1. Poisson’s ratio of MMCAluminum alloy has a melting temperature of about 550°C lower than iron. However, aluminum MMC has a higher thermalconductivity than iron. These material constraints influenced the design of the rotor. The venting structure in the rotor provides a way for the rotor to regulate its temperature. The curved vanes produce a centrifugal air pump in the rotor when rotated. This airflow created by the pump transfers heat from the rotor to the air. The heated air is then pushed out of the vent. The thermal conductivity of aluminum MMC is higher than iron, so while heat from braking is absorbed faster by an aluminum MMC rotor, heat is dissipated at a faster rate.Venting is crucial to the operation of this rotor.Figure 8. Sectioned internally vented one-piece rotorManufacturingTo manufacture a brake rotor with a high ceramic content and a function reinforcement gradient, high pressure squeeze casting is necessary. The ceramic volume fraction in the in REL rotors cannot be easily achieved by stir cast MMC. To attain the content andgradient of ceramic material, a preform of ceramic material is used. This preform gets infiltrated by aluminum in a high pressure squeeze casting. The infiltration allows the aluminum to form the matrix around the ceramic material.The method of infiltrating ceramic preforms with aluminum gives the ability to have a FRG. The infiltrated preforms are tailored to improve rotor performance. The move away from a stir-cast aluminum MMC method to a preform infiltration method, gives the ability to selectively reinforce the rotor.The aluminum MMC used in the automotive rotor is difficult to machine. Sections of the rotor, venting structure and rotor hub, are not reinforced with ceramic. These sections are not used for braking and do not require improved properties. The majority of the machining required in the non-MMC areas of the rotor.The internal venting in the one piece rotor is not machined andrequires a core. Using high pressure squeeze casting required a high strength core. A salt core had to be developed to withstand thecompressive force required, not be infiltrated, and not lose integrity with temperatures required for casting. The salt core is one piece and holds the negative pattern of the venting structure.The assembly used for casting consists of two ceramic preforms, with a salt core in the middle. The casting assembly is placed in the die and squeeze cast. The aluminum will infiltrate the preforms to create composite material, and be voided by the salt core, creating theventing structure. All other aluminum in the casting will removed orused for rotor hub.Figure 9. REL vented one-piece rotor manufacturing setupTestingThere were three types of testing done with the aluminum MMC rotors. Friction testing was done to determine the ability of a brake rotor to stop with a given set of brake pads. Integrity testing was done to observe the ability of the rotors to withstand braking before failure. Temperature testing was used to evaluate a rotors ability to manage heat added through braking. All tests were done on a brakedynamometer. Thermocouples placed in rotors and pads are used for temperature collection.Friction TestingDifferent brake pads were tested to determine the friction coefficient, brake pad wear and rotor wear when used on aluminum MMC rotors. Non-asbestos organic (NAO) brake pads are preferred for aluminum MMC rotors. Metallic and semi-metallic brake pads are not ideal for the hardness of the composite rotors. All tests shown were completed using the same compound of braking material. It is a NAO brake pad selected for its compatibility with aluminum MMCs.An aluminum MMC rotor was friction tested against a similar cast iron rotor. Both rotors were braked with the same composition of organic material and in the same caliper. The test followed the FMVSS 122 Standard, S7.1 to S7.5. After a brake warming andburnish, the effectiveness tests consisted of six stops from 48.3 km/h (30 mph) and six stops from 96.6 km/h (60 mph) initiated at 65.5°C (150°F) brake temperature. The test concludes with four 128.7 km/h (80 mph) stops and four 160.9 km/h (100 mph) stops in succession. From the test, a brake coefficient of friction for each stop iscalculated. [3]Figure 10. Cast Iron vs Aluminum MMC Friction ResultsThe cast iron and aluminum MMC rotors exhibited similar friction behavior in the test. Through the 30 mph and 60 mph stops, the coefficient of friction for both rotors varied between 0.40 and 0.44. On the 80 mph and 100 mph stops, the MMC rotor saw a steady decrease in its friction coefficient, while the cast iron rotor had a similar decrease but resisted fade better on the final stops.Integrity TestingWith a selectively reinforced rotor, there are two or more different material expansion rates in the rotor as there are two differentmaterials. When subjected to braking, the heat added to the rotor is not constant, linear, or uniform throughout the rotor. Testing on the rotor was done to determine a brake rotors behavior during a heat cycle. Organic brake pads were used. Results of the testing are determined visually. Cracking, separation, degrading, and gougingare all evaluated and compared to other rotors.Figure 11. Integrity testing separation resultsIntegrity testing done consisted of repeated braking without any external cooling. The rotor was stopped from 80 km/h (equivalent speed) at high braking pressure (4500 kPa target) until significant gouging occurred.The results of the integrity testing indicate that the selectivelyreinforced rotor will not fail under temperature change. There was no visible layer separation or significant warping. Gouging occurred at high rotor temperature (≥540°C), exceeding the degradation temperature of the brake pads used.Temperature TestingEvaluating the effectiveness of the venting structure in the rotors was done through temperature testing. The rate of cooling of a vented automotive aluminum MMC rotor was compared against a similar rotor with the venting blocked. Venting was blocked using an epoxy putty. Minimal amounts of epoxy was used, to maintain thesimilarities between the rotors. The test consisted of adding heat to arotor, through a braking cycle, then spinning the rotor at a constant speed (300 rpm). Temperatures are then monitored as the rotor cools down. No external air source was added.Table 2. Vented vs Non-vented cooldown resultsThe comparative results of the cooling of the vented and non-vented rotors showed that the vented rotor will cool faster than a non-vented rotor. This verifies development from solid rotor, to internally vented rotor.In the same manner as the previous test, a vented cast iron rotor was compared to the aluminum MMC vented automotive rotor. Therotation speed was 330 rpm with a cooling wind with of 48.3 km/h.Figure 12. Cast Iron vs Aluminum rotor cooldown resultsThe results of the second temperature test shows the difference in the cooling rates between cast iron and aluminum MMC. The aluminum MMC cooled to 100°C in about half of the time that the cast iron rotor did. This difference in cooling rates allows an aluminum MMCrotor to cool faster than a traditional brake rotor.Figure 13. Aluminum MMC rotor dynamometer testingA third temperature test was run on a dynamometer with two 280mm rotors. One rotor in the test was a prototype aluminum MMC rotor, while the second rotor, like the previous test, was a vented cast iron rotor of similar geometry. The test consisted of ten stops from 80 km/hr equivalent speed and braking with a target maximum brake line pressure of 3500 kPa. There was approximately 20 seconds between each stop. There was an external inline convective airflow produced by an industrial blower that matched the speed of the rotor,simulating the operation of a vehicle. The dynamometer flywheel hada moment of inertia of 78.25 kg*m^2.Figure 14. Aluminum MMC vs cast iron operating temperature testResults from the third temperature test show the operatingtemperatures of a vented aluminum MMC rotor against a comparable cast iron rotor in an aggressive braking test. The MMC rotordisplayed a higher temperature gain per stop than the iron rotor, but also had a greater temperature loss between stops. The cast iron rotor had higher final temperature after the test, but displayed slightlyquicker braking, finishing the test in less time than the MMC rotor.Figure 15. Iron rotor dynamometer testingProductionREL mass produces aluminum MMC motorcycle rotors following the process of squeeze casting aluminum into a ceramic, post cast machining, and heat treatment. The production of a single piecevented aluminum MMC rotor requires an extra component (salt core), two ceramic preforms, and an extra post process (salt removal). Although there are differences the production method of the single blade MMC motorcycle and the process needed for the vented MMC rotor, the method is adaptable to produce the vented MMC rotor.Production costs for a single piece vented aluminum MMC automotive rotor are higher than that of an equivalent cast iron rotor. This is due to a more extensive manufacturing process as well as more expensive materials. When compared to lightweight carbon ceramic rotors, aluminum MMC rotors are significantly cheaper. Market OpportunityNo cost effective one-piece lightweight brake rotor is currently available in the automotive market. Lightweight multi-piece composite rotors are in the high-end auto market. Development is needed to make these components more robust, accepted and cost effective. Though there is widespread demand for this sort of innovation, the expensive composite brake rotors and other lightweight automobile components are only available to the high end and niche applications.The developed lightweight automotive rotor will improve fuel efficiency by allowing for less vehicle weight, lowering the un-sprung weight for better handling and allow for even greater vehicle weight reduction elsewhere by enabling additional complementary weight saving improvements.The commercial potential of the development of a selectively reinforced aluminum composite automobile brake rotor provides a needed solution for the automobile industry. Vehicles that can be targeted for commercialization include lightweight and electric vehicles. Small lightweight vehicle are less demanding of braking systems than full size vehicles. Electric vehicles may have regenerative braking systems that will reduce the amount of braking that is done in the mechanical braking system. In both types of vehicles, electric and lightweight, there is a reduced amount of braking needed compared to a standard vehicle. With limited braking needed, lightweight and electric vehicles are an initial commercialization target for selectively reinforced aluminum composite automobile brake rotors. Beyond this initial target, vehicles from the small car to medium duty truck and military industry can also be targeted for adoption of aluminum MMC rotors. Aluminum MMC Brake DrumsBrake drums made of aluminum metal matrix composite have been developed by Century Inc. The lightweight braking solution can remove 40% of the weight of a similar cast iron brake drum. The brake drums were selectively reinforced and used ceramic preforms and squeeze casting as the method of manufacture. Vehicle and dynamometer testing showed the MMC brake drum either matched or exceeded cast iron drum performance on a 4536 kg axle load. The level of success demonstrated by this brake drum makes it a feasible for the commercial truck and military market. [2] ConclusionAluminum metal matrix composite brake rotors with a selective ceramic function reinforcement gradient have been developed to supplement the demand for light weighting in the auto industry. The development moved from proven single blade motorcycle rotor, to a solid one piece automotive rotor, an internally vented three piece automotive rotor, and finally a one piece internally vented automotive rotor. The intention of development was to produce a lightweight rotor that can be substituted for a standard cast iron rotor. The one piece internally vented rotor has a ceramic function reinforcement gradient, which tailors the MMC rotor sections to a braking cycle, as well as internal venting that will remove heat in the rotor.Rotor development also include development of manufacturing strategies to complement the rotor demands. To be selectively reinforced with a ceramic FRG, the casting method of ceramic preforms and high pressure die casting had to be optimized. Incorporation of an internal venting structure required the development of a large, high strength salt casting core. Dynamometer testing of the aluminum MMC rotor consisted of friction, integrity, and temperature testing. Friction results show that an aluminum MMC rotor and cast iron rotor have similar friction capabilities when using an organic brake pad. Integrity testing results prove that a selectively reinforced rotor can operate without failure at normal braking temperatures. Temperature testing verified the effectiveness of a venting structure as well as the faster cooling rate of an aluminum MMC rotor over a cast iron rotor. The testing results indicate that a functional reinforced aluminum metal matrix composite rotor is viable option for front and rear brake applications in the automotive market.Noise and rusting of rotors was observed during comparison testing of between cast iron and aluminum MMC rotors. The MMC rotors made considerably less noise than the cast iron rotors. While the iron rotors would squeak during braking, the MMC rotors would make a much softer light grinding sound. During storage of rotors, the iron rotors would build an oxidation layer that would be removed before braking. The aluminum MMC rotors did not have a need for oxidation to be removed.This development has been able to prove out the performance and manufacturing of a single piece vented aluminum automotive MMC rotor. Optimization of the rotor and it production process are still necessary for improvement of the product before market introduction. On-vehicle testing is the next step toward pushing development. References1. National Highway Traffic Safety Administration, “CAFÉ - FuelEconomy,” /fuel-economy, accessed Mar.2016.2. Kero, M. and Halonen, A., "Development and Testing ofLightweight Aluminum Composite Brake for Medium to Heavy Duty Vehicles," SAE Technical Paper 2010-01-1705, 2010,doi:10.4271/2010-01-1705.3. National Highway Traffic Safety Administration, Department ofTransportation., “Traffic Safety Administration Laboratory Test Procedure for FMVSS 122,” TP-122-02 August 1, 2006 Contact InformationAdam Loukusadam@Taylor Ervataylor@Luke Luskinluke@REL, Inc.57640 North Eleventh StreetCalumet, MI 49913Phone: 1-906-337-3018rel@Fax: (906) 337-2930AcknowledgementsThe authors would like to thank the Ohio State University for theirwork, support, and results in material testing and computersimulation.Additionally, the authors would like to thank the National ScienceFoundation for their funding of this development effort.The Engineering Meetings Board has approved this paper for publication. It has successfully completed SAE’s peer review process under the supervision of the session organizer. The process requires a minimum of three (3) reviews by industry experts.All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE International.Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE International. The author is solely responsible for the content of the paper.ISSN 0148-7191/2016-01-1937。