轴流涡轮叶栅端壁气膜冷却的传热研究

摘要

该文以大型低速线性涡轮叶栅为对象进行其端壁气膜冷却的传热研究.在发展一种新的测试技术的基础上,结合叶栅下游流场测量,获得了叶栅端壁上冷却膜隔热效率的分布,使得叶栅端壁上下冷却层的冷却效率可分别定量描述.以无端壁气膜冷却和畜端壁气膜冷却两种情况进行研究,对比地获得了两者的综合损耗和二次流特征区域随冷却气体供给压力和注射位置的变化规律.这种气动力损失和冷却空气损耗的定量化,可为端壁气膜冷却技术的气动力成本和冷却效益提供数据.论文还进行了叶片冷却孔质量流的测量与常静压气流混合分析,结合前述气动力损失和冷却空气损耗的测量结果表明,端壁气膜冷却的综合损失明显地由三个部分组成:叶片冷却孔内产主的损失;由于冷却空气与主流热空气的混合产生的损失;二次流的变化产生的损失.该文的研究成果显示,冷却孔内产生的损失是主要的,并且低静压区域的冷空气喷射会增加单位冷空气质量流的消耗;喷射的冷空气与叶栅端壁流场之间有强烈的相互作用;二次流对冷却空气的流动轨迹有较强的影响;冷空气喷射能延缓端壁入口边界层的三维分离、改变二次流从而减少其相关损耗.

目录

文摘

英文文摘

DEDICATION

Preface

Nomenclature

Table of Figures

1 History and development of the gas turbine

1.1 Introduction

1.2 Development of Gas Turbines From 1791 to 1930

1.3 Development of Gas Turbines From 1930 to 1940

1.4 Development of Gas Turbines From 1940 to 1945

1.5 Development of Gas Turbines From 1945 to 1950

1.6 Development of Gas Turbines From 1950 to 1960

1.7 Development of Gas Turbines From 1960 to 1970

1.8 Development of Gas Turbines From 1970 to 1980

1.9 Development of Gas Turbines From 1980 to 1990

1.10 Development of Gas Turbines in 1990s

2 Compressors

2.1 Compressors

2.2 Compressor Performance

2.3 Energy Transfer

2.4 Blade Notation for Ideal Axial-flow Compressors

2.5 Velocity Diagram for Axial-flow Compressor

2.6 Flow Coefficient

2. 7Mach Number

2.8 De Hailer Number

3 Turbines

3.1 General

3.2 Turbine Performance

3.3 Blade Notation for Axial-flow Turbines

3.4 Stage Velocity Diagram for an Axial-flow Turbine

3.5 Turbine Cooling

3.6 Turbine Cooling Techniques Using Air as Coolant

3.7 Liquid-Cooled Turbine Blades

4 Endwall Film-Cooling

4.1 Introduction

4.2 Endwall Heat Transfer

4.3 Endwall Film-cooling

4.3.1 Film-Cooling Details

4.3.2 Alternative Methods of Endwall Cooling

4.3.3 Research Objectives

4.4 Examples

4.4.1 Example 1

4.4.2 Example 2

4.5 The Cooling Benefits of Endwall Coolant Ejection

4.6 The Aerodynamic Costs of Endwall Coolant Ejection

5 Conclusions

5.1 Conclusions

References