水利水电毕业设计外文文献翻译

水工建筑物，29卷，9号，1995

旋涡隧道溢洪道。液压操作条件

M . A .戈蓝，B. zhivotovskii，我·诺维科娃，V . B .罗季奥诺夫，和NN罗萨娜娃

隧道式溢洪道，广泛应用于中、高压液压工程。因此研究这类溢洪道这是一个重要的和紧迫的任务，帮助在水工建筑中使用这些类型的溢洪道可以帮助制定最佳的和可靠的溢洪道结构。有鉴于此，我们希望引起读者的注意，基本上是新的概念（即，在配置和操作条件），利用旋涡流溢洪道[1，2，3，4 ]。一方面，这些类型的溢洪道可能大规模的耗散的动能的流动的尾段。因此，流量稍涡旋式和轴向流经溢洪道的尾端，不会产生汽蚀损害。另一方面，在危险的影响下，高流量的流线型面下降超过长度时，最初的尾水管增加的压力在墙上所造成的离心力的影响。一些结构性的研究隧道溢洪道液压等工程rogunskii，泰瑞，

tel'mamskii，和tupolangskii液压工程的基础上存在的不同的经营原则现在已经完成了。这些结构可能是分为以下基本组：

-涡旋式（或所谓的single-vortex型）与光滑溢洪道水流的消能在隧道的长度时的研究的直径和高度的隧道；参看。图1），而横截面的隧道是圆或近圆其整个长度。涡旋式溢洪道-与越来越大的能量耗散的旋涡流在较短的长度- <（60——80）高温非圆断面导流洞（马蹄形，方形，三角形），连接到涡室或通过一个耗能（扩大）室（图2）[ 5，6 ]或手段顺利过渡断[ 7]；-溢洪道两根或更多互动旋涡流动耗能放电室[ 8 ]或特殊耗能器，被称为“counter-vortex耗

能”[ 2，4 ]。终端部分尾水洞涡流溢洪道可以构造的形式，一个挑斗，消力池，或特殊结构取决于流量的出口从隧道和条件的下游航道。液压系统用于链接的流量的尾管可能涉及可以使用overflowtype或自由落体式结构。涡旋式溢洪道光滑或加速[ 7 ]能量耗散的整个长度的水管道是最简单和最有前途的各类液压结构。设计技术涡溢洪道已开发和出版了许多研究[ 2，7，8 ]；特别是，技术是目前可用于计算液压阻力的路线和流动率，涡旋式流量和压力。然而，每一个实际工程设计结构也必须进行评估。模型调查手段，因为它仍然是不可能评估所有的因素的操作溢洪道计算方式。因此，让我们一起关注一些重要理论问题。熟悉这些主题可以协助设计和研究涡式溢洪道。

评价设计溢洪道的尺寸。选择一个特定的溢洪道类型取决于很多因素，如有效的水头，巨大的escapage放电，这是配置的液压项目（例如，使用一个河引水隧道在运营期间或的水管道水力发电厂在施工期间），在放电的流入尾水渠道，地形及地质特征（特别是可能的长度，尾水腿），和技术经济特点。

入口（入口段的形式，表面或地下输）。入口的设计是根据设计规范。其目的在保持其运输能力时，运作中的水能自由下泄。轴（垂直或倾斜）。轴的直径是由近等于尾水管的直径。最大平均流量在一个轴的范围是15 - 20米/秒。涡流产生装置。整个长度的尾段溢洪道，以及一定程度的洪水的轴（即，其水力工况Q

分地区。；尾水隧道管道以外的涡流发生器；倾斜角度轴引水管道的涡轴发电机。运动学特征旋涡流动和运输能力取决于一个重要的溢洪道。对涡流产生装置的设计。该系数的tangential-type涡流生成脑电图=安全装置。，图（图3）；这里是平均流量在一个圆形出口段的涡流节点）。应该指出的是，涡流节点设计=空调机作用，哪里是问是价值的几何参数该涡流发生器需要维持所需的预旋流动。例如，tupolangskii涡旋式溢洪道，Areq=1.4；为tel'mamskii水利工程，Areq =0.6；并为rogunskii溢洪道，应安排为：Areq =1.1。

另一个特征参数的旋转度对溢洪道的尾段，是积分流旋转参数的二[ 1，

2 ]。预旋17后面0涡生成装置在距离3.0dt从轴的轴可能的基础上确定的图形依赖性：（图4）。整体宽度的隧道被确定类型的溢洪道设计和选择整体宽度的隧道被确定类型的溢洪道设计和选择。该方法决定耗散过剩能量（无论是均匀或越来越密集耗散）。横截面面积的终端部分的尾水隧洞确定等效直径。消能室。选择设计的尺寸取决于速度旋转流入口和后室长度的尾水隧洞。对尾水隧洞，最好的方法是使用一个渐缩管（或圆柱）段为共轭条件之间的切向涡轮发电机和消能室。本部分将负责以下功能：使减少旋转速度的水流进入消能室，均衡流量转向最大轴部分的流动速率的中央部分，并减少其动态载荷在旋转节点的流量。

从上述讨论如下，在这些案件中没有空气压迫，涡旋式溢洪道可能是模仿方面的所有要求的标准。情况是不同的，在案件的掺气水流，这也是难以模型。

在水力模型外部大气压力时，空气的体积含量略有不同的流动是矿井下运输的关键的部分，而在物理结构，包埋空气，向下移动，压缩的增加液体压力。因此，在方案的溢洪道在泰瑞水利工程（图1），百分压的物理结构是高达15倍，而在开放模型建造一个1 : 60规模，压缩的百分点在1.4 - 1.5范围，即，十分之一的价值发现的领域。此外，在实验中使用的模型，有增加指出在角度的旋转流动中的初始段的尾水隧洞为不良影响，排放减少的内容和空气的混合物增加。因为在物理对象中空气含量的关键部分都是微不足道的。建立一个可靠的模型vortextype当有一个自由的水平在茎轴和多余的的空气的流动，它是必要的隔离该地区的空气在上部和下部的区域，从外部环境，在这些地区减少空气压力根据几何尺度建立一个真空的模型。

溢洪道水力条件的部分。液压操作条件的涡旋式溢洪道不同于相应条件构造配置传统的溢洪道。考虑到这些差异的基础上的结果，实验室研究工作的rogunskii溢洪道水力发电厂（包括消能室）和溢洪道的水力工程（，泰瑞经营着均匀的能量耗散整个隧道的长度）。初步设计的rogunskii水电厂称为槽的末端结构的专业溢洪道；它的目的是，使结束流动率达到60米/秒。可以理解的是，流动率是需要采用特殊的保护措施的流线型表面溢洪道避免气蚀损伤。为了满足这一需要，塔什干水电局工作，与该公司的流体力学研究（现在中央水利学院，社会科学研究所的建设，发展经济学）几种版本的溢洪道设计旨在消除的一个重要部分的能量范围内的流动。通过溢洪道和大大减少流量的尾水隧洞，排入河道。在这个研究中，为了弯曲的转折段，传统配置一个竖井溢洪道取而代之的是一个切向流涡流发生器。同样的。涡旋式流创建整个长度的尾段。液压研究进行了一个模型，模拟了竖井溢洪道在1 : 50的比例和包括一个轴测量直径13米，高148米，切涡流产生装置，和尾水隧洞。

研究表明，在进行轴的送水流量旋转节点，中间水位保持在流量小于设计速度。这台标记的大小取决于该escapage放电和抵抗的溢流段位于一个较低的水平。在模型几乎完全封闭的空间。此外，较低水平的水，空气越多限制水的流量将流入旋转节点。稳定旋涡流动与周围的水环境和内部气体，核心是形成超越切涡流发生器。由于不对称输水进入涡流发生器在最初的部分，核心的流动是非圆，位于远离中心截面的位置。整个圆柱段长度的管道，气体气芯具有一个波浪状弯与曲轴线相吻合与隧道轴线甚至接近10dx从轴的轴。作为nonaerated流

进入尾管通过旋转的节点，一个真空计压力是建立在燃气蒸汽的核心，并在案件高度曝气。

减少压力的燃气蒸汽的核心是与离心力的作用，在涡旋式流动，同时增加了压力与几乎完全释放空气曝气流量为核心引起的运输气泡从外围向中心的作用下的压力梯度。一尾管圆柱起始段，自由区下游从0.7增加的部分距离1.3dv从轴轴0.77的部分在距离12.4dr，而角旋转流和轴向和周向流动率下降。在一个锥形的部分。相对面积的气体从0.987下降到0.874，长度的锥形部分，而角旋转流减少之间的一半和三分之二的初始值的这一段。一个专用的建筑，是提出了在本文章的存在是一个能量耗散腔中的涡旋式水流突然膨胀，迅速转化为轴向流动放电流量从尾水隧洞直接进入大气层。平等的离心加速度的自由落体加速度是一个必要条件的崩溃涡结构的流动的隧道。一旦达到平等，水沿隧道顶“洞穴中，“混合容易与空气中的流动的核心。改造旋涡状流入轴向流发生。这时伴随着显着的能量耗散。在一个系统的一个锥形涡发生器和消能室后面的发电机，86%的初始能量的流动消散，因为它穿过这段。分布的静态压力的轴是几乎相同的版本。分布的静态压力在水洞中取决于设计的隧道和流动程度的旋转。系统的越来越多的能量耗散。

结论

我们考虑了溢洪道使我们有效的保证耗散过剩的动能和结构整体可靠性。运行可靠性的基础上，涡溢洪道消能在水洞中设计，被认为在目前的文章中证实了这一事实，压力波动和强度的湍流耗散顺利整个隧道，这些数量的低水平点放电的流动到下一池。强行配置一个旋流泄，是一个水利工程决定性的条件。

Hydrotechnical Construction, V ol. 29, No. 9, 1995

VORTEX-TUNNEL SPILLWAYS. HYDRAULIC OPERATING CONDITION S

M. A. Galant, B. A. Zhivotovskii,

I. S. Novikova, V. B. Rodionov,

and N. N. Rozanova

Tunnel spillways are widely used in medium- and high-pressure hydraulic works. It is therefore an important and

pressing task to improve the constructions used in these types of spillways and to develop optimal and reliable spillway

structures.

With this in mind, we would like to turn the reader's attention to essentially novel (i.e., in terms of configuration and

operating conditions) vortex spillways which utilize vortex-type flows [1, 2, 3, 4]. On the one hand, these types of spillways

make possible large-scale dissipation of the kinetic energy of the flow on the initial leg of the tailrace segment, and, as a

consequence, flow rates of slightly vortex-type and axial flows through the subsequent legs that do not produce cavitation

damage. On the other hand, the dangerous effect of high flow rates on the streamlined surface decreases over the length of

the initial tailrace leg as a consequence of the increased pressure on the wall caused by the effect of centrifugal forces.

A number of structural studies of tunnel spillways for hydraulic works such as the Rogunskii, Teri, Tel'mamskii, and

Tupolangskii hydraulic works based on different operating principles have now been completed. These constructions may be

divided into the following basic groups:

- vortex-type (or so-called single-vortex type) spillways with smooth dissipation of the flow energy throughout the

length of the tunnel when L r > (60 -- 80)hT or (60 -- 80)dT (where dT and hT are the diameter and height of the tunnel; cf.

Fig. 1), while the cross-section of the tunnel is either circular or near-circular throughout its length.

- vortex-type spillways with increasingly greater dissipation of the energy of the vortex-type flow over a shorter

length Lr -< (60 -- 80)hT of a noncircular section river diversion tunnel (horseshoe-shaped, square, triangular) which is

connected to the eddy chamber either by means of an energy-dissipation (expansion) chamber (Fig. 2) [5, 6] or by means of

a smooth transition leg [7];

- spillways with two or more interacting vortex-type flows in energy-dissipation discharge chambers [8] or in special

energy dissipators that have been termed "counter-vortex energy dissipators" [2, 4].

The terminal portion of the tailrace tunnel of a vortex spillway may be constructed in the form of a ski-jump bucket,

a stilling basin, or special structures depending on the flow rate at the exit from the tunnel and on the conditions in the

channel downstream. The hydraulic system used to link the flow to the tailrace canal may involve the use of either overflowtype

or free-fall type structures.

V ortex spillways with smooth or accelerated [7] dissipation of energy over the entire length of the water conduit

represent the simplest and most promising types of hydraulic structures. Techniques of designing vortex spillways have now been developed and published in numerous studies [2, 7, 8]; in

particular, techniques are now available for calculating the hydraulic resistance of individual legs of a route and the flow rates

and pressures in vortex-type flow. However, for each actual hydraulic project a designed structure must also be evaluated by

means of model investigations, since it is still not possible to evaluate all the elements of the operation of a spillway by

means of calculations.

Thus, let us turn our attention to a number of theoretically important problems. A familiarity with these topics will

be of assistance in the design and investigation of vortex spillways. Evaluation of the Design and Geometric Dimensions of the Elements of a Spillway. The selection of a particular

type of spillway depends on a number of factors, such as the effective head, the magnitude of the escapage discharge, the

configuration of the hydraulic project (for example, the use of a river diversion tunnel during the operational period or of the

water conduits of hydroelectric power plants in the construction period), conditions in the discharge of the flow into the

tailrace channel, topographic and geological features (in particular, the possible length of the tailrace leg), and the technical

and economic characteristics.

Inlet (entry segment in the form of surface or subsurface offtake). The inlet is designed on the basis of standard

techniques to maintain its conveyance capacity when functioning in the free-fall regime. Shafts (vertical or inclined). The diameter of the shaft is made nearly equal to the diameter of the tailrace leg:

It should be noted that the eddy node is designed so that A = Areq, where Are q is the value of the geometric parameter of the vortex generator needed to maintain the required prerotation of the flow. For example, for the conditions of the Tupolangskii vortex-type spillway, Are q = 1.4; for the Tel'mamskii hydraulic works, Are q = 0.6; and for the Rogunskii spillway, Ar:q = 1.1.

A second parameter which characterizes the degree of rotation of the flow on individual legs of the tailrace segment is the integral flow rotation parameter II [1, 2]. The prerotation 17 0 behind the vortex generating device at a distance 3.0dT

from the axis of the shaft may be determined on the basis of graphical dependences thus: 17_o = f(A) (Fig. 4).Tailrace tmmd. The overall widths of the tunnel are determined by the type of spillway design which is selected and the method decided on for dissipation of the excess energy (either by means of smooth or increasingly more intensive dissipation). Energy Dissipation Chamber. The choice of design and dimensions depends on the rate of rotation of the flow at the inlet to the chamber and on the length of the tailrace tunnel following the chamber. For a tailrace tunnel with LT/d T _< 60, it is best to use a converging tube (or cylindrical) segment as the conjugating element between the tangential vortex generator and the energy dissipation chamber. The segment will be responsible for the following functions: reduction of the rate of rotation of the flow at the inlet to the energy dissipation chamber, equalization of flow rates accompanied by a shift in the maximum axial component of the flow rate into the central portion, and reduction of the dynamic loads at the rotation node of the flow.

From the foregoing discussion it follows that in those cases in which there is no entrapment of air, vortex spillways

may be modeled with respect to all the required criteria.

The situation is different in the case of aerated flow, which is also difficult to model. In hydraulic models with

external atmospheric pressure, the volumetric content of air varies slightly as the flow is transported down the shaft to the

critical section, whereas in the physical structure, the entrapped air, moving downwards, is compressed by the increasing

pressure of the liquid. Thus, in the case of the spillway at the Teri hydraulic works (Fig. 1), the percent compression in the physical

structure is as much as 15-fold, whereas in the open model constructed on a 1:60 scale, the percent compression is in the range 1.4-1.5, i.e., one-tenth that of the values found in the field. Moreover, in the experiments using the models, there was an increase noted in the angles of rotation of the flow in the initial segment of the tailrace tunnel as the escapage

discharge was decreased and the content of air in the mixture was increased.

Inasmuch as in the physical object the air content in the critical section is always insignificant, the increase in the

angles of rotation as the volume of escapage discharge was decreased was unexpected. To create a reliable model of vortextype

flow when there is a free level in the stem of the shaft and abundant air entrapment by the flow, it is necessary to isolate

the region of air in the upper and lower ponds from the external atmosphere and to reduce the air pressure in these regions

through creation of a vacuum in accordance with the geometric scale of the model. Hydraulic Conditions throughout the Spillway Segment. The hydraulic conditions of operation of vortex spillways

differ substantially from the corresponding conditions for spillways constructed in the traditional configuration. Let us

consider these differences on the basis of the results of laboratory studies of the operational spillways of the Rogunskii

hydroelectric plant (which includes an energy dissipation chamber) and the spillway of the Teri hydraulic works (which

operates with smooth dissipation of energy throughout the length of the tunnel).

The initial design of the Rogunskii hydroelectric plant called for a chute as the terminus structure of the operational

spillway; it was intended that the flow rate at the end of the chute was to reach 60 m/sec. Understandably, flow rates that are

this high entail adoption of special measures to protect the streamlined surfaces of the spillway from cavitation damage and the stream course from dangerous degradation. To meet this need, the Tashkent Hydroelectric Authority, working with the Division of Hydrodynamic Research (now the Central Hydraulic Institute, Society of the Scientific Research Institute on the Economics of Construction), developed several alternative versions of spillway designs intended to dissipate a significant portion of the energy of the flow within the spillway and to substantially reduce the flow rate in the tailrace tunnel and at the point where the flow is discharged into the

stream course. In one of the versions that were considered, the bend in the turning segment that is part of the traditional configuration of a shaft spillway was replaced by a tangential flow vortex generator. Similarly. vortex-type flow is created throughout the entire length of the tailrace segment. Hydraulic studies were performed on a model that simulated a shaft spillway at a scale of 1:50 and consisted of a shaft measuring 13 m in diameter and 148 m in height, a tangential vortex generating device, and a tailrace tunnel.

The studies that were performed showed that in the shaft which delivers water to the flow rotation node, an intermediate water level is maintained when the flow rate is less than the design rate. This bench mark depends on the magnitude of the escapage discharge and the resistance of the spillway segment situated at a lower level . In the constructions that have been considered here, maximum (design) flow rates through the shaft are achieved when the shaft is flooded and there is no access to the air. In the model nearly complete entrapment of air from the water surface occurred with intermediate water levels in the shaft; moreover, the lower the level of the water surface, the more the air restrained the water flow and transformed the flow into a rotation node (Fig. 7). Stable vortex-type flow with a peripheral water ring and internal gas-vapor core is formed beyond the tangential vortex generator. Due to

asymmetric delivery of water into the vortex generator in the initial segments, the core of the flow is noncircular and situated away from the center of the cross section. Throughout the length of the initial cylindrical segment of the conduit, the gas-vapor core possesses a wave-like curved axis which coincides with the axis of the tunnel even as close as 10dx from the axis of the shaft. As nonaerated flow enters the tailrace conduit through the rotation node, a vacuum-gauge pressure is established in the gas-vapor core, and in the case of highly aerated flow, gauge pressure, The reduction in pressure in the gas-vapor core is associated with the effect of centrifugal forces in vortex-type flow, while an increase in pressure is associated with nearly complete release of air from the aerated flow into the core induced by the transport of air bubbles from the periphery to the center under the effect of the pressure gradient.

For a tailrace conduit with cylindrical initial segment, the free area downstream increases from 0.7 in the section at a distance 1.3dv from the axis of the shaft to 0.77 in the section at a distance 12.4dr, while the angle of flow rotation and the axial and circumferential flow rates all decrease. In the case of a conical initial segment, the relative area of the gas-vapor core decreases from 0.987 to 0.874 over the length of the conical segment, while the angle of flow rotation decreases to

between one-half and two-thirds its initial value over this segment.

A characteristic feature of the construction that is being proposed in the present article is the presence of an energy dissipation chamber in which vortex-type flow experiences an abrupt expansion and is rapidly transformed into axial flow if the discharge of flow from the tailrace tunnel is directed into the atmosphere.

Equality of the centrifugal acceleration to the free fall acceleration is an essential condition for breakdown of the

vortex structure of the flow in the tunnel. Once equality is achieved, the mass of water traveling along the roof of the tunnel "caves in," and mixes easily with the air in the flow core. The transformation of

vortex-like flow into axial flow that occurs here is accompanied by significant dissipation of energy.

The rate of energy dissipation differs between the two versions that are being considered here (Fig. 8). In the case of a cylindrical initial segment, energy dissipation occurs smoothly, with only 60% of the initial energy of the flow dissipating over a distance of 15dw (Fig. 8a). In a system with a conical vortex generator and energy dissipation chamber behind the generator, 86% of the initial energy of the flow dissipates as it travels through this segment,

CONCLUSIONS

Application of the constructions ot vortex tunnel spillways that we have considered enable us to ensure effective

dissipation of the excess kinetic energy and overall reliability of the structure. The operating reliability of vortex spillways that are based on energy dissipation in the tailrace tunnel in accordance with the schemes that have been considered in the present article is confirmed by the fact that the pressure fluctuations and the intensity of the turbulence dissipate smoothly throughout the tunnel and by the fact that these quantities are low level at the point of discharge of the flow into the lower pond. The conditions imposed by the configuration of a vortex spillway that is part of a hydraulic project are of decisive importance in deciding which energy dissipation scheme to adopt.