变径孔射流冲击冷却的流动与传热特性数值研究  

Numerical Investigation on Flow and Heat Transfer Characteristics of Jet Impinging Cooling through Variable-diameter Hole

作　　者：席雷 高源 赵振 高建民[1] 徐亮 李云龙[1] XI Lei;GAO Yuan;ZHAO Zhen;GAO Jian-min;XU Liang;LI Yun-long(School of Mechanical Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西安交通大学机械工程学院,西安710049

出　　处：《汽轮机技术》2024年第3期186-192,共7页Turbine Technology

基　　金：陕西省自然科学基础研究计划青年项目(2022JQ-545);西安交通大学基本科研业务费基础研究专项(xzy012023071);国家重点研发计划(2021YFF0602301)。

摘　　要：采用数值方法开展了变径孔射流冲击冷却的流动与传热性能研究。设计了3种变径孔射流冲击冷却结构,即收缩孔、直孔、扩张孔。对比了不同雷诺数情况下3种孔型射流冲击冷却的流动与传热特性。分析了雷诺数和孔型对射流冲击冷却流动性能、传热性能和综合热力性能的影响。拟合得到了不同孔型冲击冷却的平均努塞尔数、压力损失系数和综合热力系数有关于雷诺数的经验关联式。结果表明:与直孔冲击冷却相比,雷诺数为6000~30 000时,收缩孔冲击冷却的压力损失系数增加了约16.67倍~21.09倍,靶面平均努塞尔数提升了约0.96倍~1.85倍;扩张孔冲击冷却的压力损失系数降低了约22.55%~33.68%,靶面平均努塞尔数降低了约5.62%~10.85%。在3种孔型中,收缩孔冲击冷却的传热性能最优、流动性能最差,直孔冲击冷却的传热性能和流动性能都处于中等水平,而扩张孔冲击冷却的传热性能最差、流动性能最好。当雷诺数小于24 000时,扩张孔冲击冷却的综合热力性能最优,其次为直孔冲击冷却,而收缩孔冲击冷却的综合热力性能最差。当雷诺数大于等于24 000时,3种孔型冲击冷却的综合热力性能很接近。研究结果可以为未来先进燃气轮机内部变径孔冲击冷却的设计提供一定的参考。A numerical investigation was conducted to study the flow and heat transfer performance of impinging jet cooling using variable-sized holes.Three different hole configurations,namely contraction hole,straight hole,and expansion hole,were designed for the impinging jet cooling system.The flow and heat transfer characteristics of the three hole configurations under different Reynolds numbers were compared.The effects of Reynolds number and hole configuration on the flow performance,heat transfer performance,and overall thermal performance of the impinging jet cooling were analyzed.Empirical correlations for the average Nusselt number,friction coefficient,and overall heat transfer coefficient of the different hole configurations were obtained as functions of the Reynolds number.The results showed that compared to the straight hole configuration,the friction coefficient of the contraction hole configuration increased by approximately 16.67 to 21.09 times,and the average Nusselt number on the target surface increased by approximately 0.96 to 1.85 times for Reynolds numbers ranging from 6,000 to 30,000.On the other hand,the friction coefficient of the expansion hole configuration decreased by approximately 22.55%to 33.68%,and the average Nusselt number on the target surface decreased by approximately 5.62%to 10.85%.Among the three hole configurations,the contraction hole configuration exhibited the best heat transfer performance but the poorest flow performance.The straight hole configuration showed moderate heat transfer and flow performance,while the expansion hole configuration exhibited the lowest heat transfer performance but the best flow performance.When the Reynolds number was less than 24,000,the expansion hole configuration had the best overall thermal performance,followed by the straight hole configuration,while the contraction hole configuration had the worst overall thermal performance.When the Reynolds number was greater than or equal to 24,000,the overall thermal performance of the three hole configurati

关 键 词：冲击冷却 单孔射流 变径孔 流动性能 传热性能 

分 类 号：TK47[动力工程及工程热物理—动力机械及工程]