流体力学的学习方法

高等流体力学

1．3．3Method in Fluid Mechanics General

一：Experiments and Observation

b Experiments(Scaling experiments)，实验本人不信，别人相信，而计算自己相信，

别人不相信。

2.Field Experiments

3.Field Observation

Objects: 1) Finding New Phenomena

2) Verifying New Hypothesis, Theories and Results

Steps: 1) Fixing programs(Objectives, Aims, Goals, Procedure, Time table)

2) Preparing Set-ups and Instruments(Equipments): LDV=Laser Doppler

Velocimeter, PIV=Particle Image Velocimeter

3) Recording Data

4) Processing Data (发展方向，用不完全数据获取信息，新技术：4－D

Assimilation 四维同化)

5) Analyzing Results

Key points of Experimental work

1. Making clear objectives and limitations 交通流的时间序列问题

2. Having exactness and exclusiveness

3. Having simplicity and practicability

4. Having reproducibility and Rebustness

5. Noticing ordinary and unparticular, extraordinary results

二：Chance Finding

Necessary conditions for grasping chances

1.Foundation of knowledge

2.Fast response to extraordinary phenomena

3.Diverge thinking

Key points

1.Having Imagination, Bold practice

2.Looking highly upon academic facts, Trying to find truth and making practice

3.Trying to verifying the hypothesis carefully

4.Disregarding errors or mistakes in time and following truth

5.Summarizing results in time

三：Imagination/Imaging

Imagination=creatively thinking

Creation ability=Amount of knowledge ×Divergent thinking

Origins of Imagination

1.Stimulation of difficulties

2.Encourage of curiosity

3.Thinking unceasingly

4.Inspiration of discussion

四：Reasoning methodically

Classification of Reasoning

1.Deduction type

2.Induction type reasoning

3.Analogy type thinking

4.Reduction to absurdity

Key points of Reasoning

1.Based on sufficiently large amount of facts

2.Based on correct hypothesis or assumptions

3.Based on correct logic

4.According confusion of facts and explained facts

五：Summarizing Rules and Laws

Key points of summarizing

1.Based on derived(computed) or explained(observed) facts

2.Revealing basic functional relations Cause-Results-Relations

3.Be clear, Exact ,Concise

科技论文的八股

Eight Key Points for Scientific Writing

1.Title: concise, concrete (English: 15-20 words, Chinese: 15-20 characters)

2.Abstracts: purpose, methods, results,(EI: 150words, 结果现在时，工作过去时)

3.Introduction: 引言部分，一定要有，占全文五分之一，Motion, previous works, present

4.Context: Experiment, apparatus-procedure-results

5.Conclusions 现在时或者现在完成时，不要和引言重复，

6.Acknowledgement

7.References

8.Appendices

特别的，引言，结论不能重复。

§1.3.4 流体力学方法论：特殊方法

●Lagrange描述和Euler描述

Lagrange描述：基于流体质点运动轨迹的描述；

Euler描述：基于场论的描述。

●无量纲化

量纲分析：流体力学的基础；

流体力学的基本量纲：时间、长度、质量、温度；

无量纲化：解决一切已建模的流体力学问题的首要步骤。

无量纲化的主要步骤：

1）确定问题中的特征量；

2）给出所有物理量（自变量、因变量）的无量纲形式；

3）将问题中的方程无量纲化；

4）提炼无量纲方程和定解条件中的无量纲组合（无量纲

数）；

5）对问题做简化或直接求解。

实例：Navier-Stokes方程的无量纲化：

∇v

⋅

=