V形腔中的自然对流和传热
发布时间：2021-07-26 10:44
地球的地理结构很复杂,地表面通常是倾斜的,特别是在山地、山谷、河流或湖泊地区。此外,由于地球表面温度通常随时间变化,倾斜表面的温度大于上方流体（可能是空气或水）的温度时,较热的表面加热流体,从而产生沿倾斜表面向上的流动,称为上坡流。另一方面,如果倾斜表面的温度低于上述流体的温度,则较冷的表面冷却流体,并沿着倾斜表面向下流动,形成下坡流。这种上坡流和下坡流是山谷或河流流域中斜坡流动的典型情况。斜坡流在传热传质中起着关键作用,特别是在大气中的污染物输送,因此斜坡流是理解V形几何形状流动过程的基础。另外,腔体中由浮力引起的流体运动在自然界和工程中有广泛的应用。大量的文献对由于内力或外力作用,不同的几何形状以及时间条件（定常或非定常）引起的流动进行研究。由于自然对流在许多工业过程中有重要应用,大多数研究者已经考虑过与水平或垂直热壁相邻的自然对流流动。然而,针对斜坡边界对自然对流流动的影响,矩形腔体模型并不适用。因此,三角形腔内的自然对流流动收到广泛关注。同时,地球表面通常很复杂,这些规则的几何形状在大多数地理环境中并不适用,其中倾斜的几何形状对系统有重要影响。特别地,V形腔中的自然对流也受到关...
【文章来源】：北京交通大学北京市 211工程院校 教育部直属院校
【文章页数】：206 页
【学位级别】：博士
【文章目录】：
Acknowledgements
ABSTRACT
Chinese Abstract
Nomenclature
1 Introduction
1.1 Problem description
1.1.1 Flow phenomena in a V-shaped topography
1.1.2 Natural convection in a V-shaped cavity
1.2 Literature Review
1.2.1 Natural phenomena on an inclined topography
1.2.2 Natural convection on an incline wall or in a cavity with an inclined wall or more
1.2.3 Analytical methods of natural convection
1.3 Summary of literature review
1.4 Objectives and outline of the present study
2 Analytical,numerical and experimental procedures
2.1 Formulation
2.1.1 Governing equations
2.1.2 Appropriate assumptions
2.2 Scaling Analysis
2.3 Numerical approach
2.3.1 Numerical Schemes
2.3.2 Convergence criterion
2.4 Experimental procedure
2.4.1 Experimental model
2.4.2 Measurement techniques
2.4.3 Experimental arrangements
2.5 Summary
3 Transient natural convection of initially stratified fluid in a V-shaped cavity
3.1 Physical model and scaling analysis
3.2 Validation
3.3 Development of transient natural convection
3.3.1 Flow structure
3.3.2 Temperature and velocity
3.3.3 Time of the stratification breakup
3.4 Heat and mass transfer
3.5 Summary
4 Transition to an unsteady flow in a two-dimensional V-shaped cavity
4.1 Transition to an unsteady flow for air
4.1.1 Mesh and time step
4.1.2 Validation
4.1.3 Numerical results and discussion
4.1.4 Heat and mass transfer
4.2 Transition to an unsteady flow for water
4.2.1 Mesh and time step
4.2.2 Validation
4.2.3 Numerical results and discussion
4.2.4 Heat and mass transfer
4.3 Summary
5 Transition to an unsteady flow in a three-dimensional V-shaped cavity
5.1 Physical model and formula
5.2 Transition to an unsteady flow for air
5.2.1 Mesh and time step
5.2.2 Validation
5.2.3 Numerical results and discussion
5.2.4 Heat and mass transfer
5.3 Transition to an unsteady flow for water
5.3.1 Mesh and time step
5.3.2 Validation
5.3.3 Numerical results and discussion
5.3.4 Heat and mass transfer
5.4 Summary
6 Experimental study of the transition to an unsteady flow
6.1 Flow visualizations and temperature measurements with thermistor
6.1.1 Steady state
6.1.2 Unsteady state
6.2 Summary
7 Conclusions
7.1 Summary of the present research
7.1.1 Natural convection of initially stratified fluid
7.1.2 Transition to an unsteady flow
7.2 Future studies
References
The author's resume and research results obtained during his Ph.D
学位论文数据集
【参考文献】：
期刊论文
[1]THE PHYSICAL STRUCTURE OF THE WINTER FOG IN CHONGQING METROPOLITAN AREA AND ITS FORMATION PROCESS[J]. 李子华,张利民,张庆鸿. Acta Meteorologica Sinica. 1994(03)
本文编号：3303415
【文章来源】：北京交通大学北京市 211工程院校 教育部直属院校
【文章页数】：206 页
【学位级别】：博士
【文章目录】：
Acknowledgements
ABSTRACT
Chinese Abstract
Nomenclature
1 Introduction
1.1 Problem description
1.1.1 Flow phenomena in a V-shaped topography
1.1.2 Natural convection in a V-shaped cavity
1.2 Literature Review
1.2.1 Natural phenomena on an inclined topography
1.2.2 Natural convection on an incline wall or in a cavity with an inclined wall or more
1.2.3 Analytical methods of natural convection
1.3 Summary of literature review
1.4 Objectives and outline of the present study
2 Analytical,numerical and experimental procedures
2.1 Formulation
2.1.1 Governing equations
2.1.2 Appropriate assumptions
2.2 Scaling Analysis
2.3 Numerical approach
2.3.1 Numerical Schemes
2.3.2 Convergence criterion
2.4 Experimental procedure
2.4.1 Experimental model
2.4.2 Measurement techniques
2.4.3 Experimental arrangements
2.5 Summary
3 Transient natural convection of initially stratified fluid in a V-shaped cavity
3.1 Physical model and scaling analysis
3.2 Validation
3.3 Development of transient natural convection
3.3.1 Flow structure
3.3.2 Temperature and velocity
3.3.3 Time of the stratification breakup
3.4 Heat and mass transfer
3.5 Summary
4 Transition to an unsteady flow in a two-dimensional V-shaped cavity
4.1 Transition to an unsteady flow for air
4.1.1 Mesh and time step
4.1.2 Validation
4.1.3 Numerical results and discussion
4.1.4 Heat and mass transfer
4.2 Transition to an unsteady flow for water
4.2.1 Mesh and time step
4.2.2 Validation
4.2.3 Numerical results and discussion
4.2.4 Heat and mass transfer
4.3 Summary
5 Transition to an unsteady flow in a three-dimensional V-shaped cavity
5.1 Physical model and formula
5.2 Transition to an unsteady flow for air
5.2.1 Mesh and time step
5.2.2 Validation
5.2.3 Numerical results and discussion
5.2.4 Heat and mass transfer
5.3 Transition to an unsteady flow for water
5.3.1 Mesh and time step
5.3.2 Validation
5.3.3 Numerical results and discussion
5.3.4 Heat and mass transfer
5.4 Summary
6 Experimental study of the transition to an unsteady flow
6.1 Flow visualizations and temperature measurements with thermistor
6.1.1 Steady state
6.1.2 Unsteady state
6.2 Summary
7 Conclusions
7.1 Summary of the present research
7.1.1 Natural convection of initially stratified fluid
7.1.2 Transition to an unsteady flow
7.2 Future studies
References
The author's resume and research results obtained during his Ph.D
学位论文数据集
【参考文献】：
期刊论文
[1]THE PHYSICAL STRUCTURE OF THE WINTER FOG IN CHONGQING METROPOLITAN AREA AND ITS FORMATION PROCESS[J]. 李子华,张利民,张庆鸿. Acta Meteorologica Sinica. 1994(03)
本文编号：3303415
本文链接：https://www.wllwen.com/kejilunwen/dongligc/3303415.html
