摘要: |
以双层壳型冲击/气膜复合冷却结构的平壁模型作为研究对象,进行了该种结构典型冷却单元的放大模型实验研究。通过改变冲击Re数(10 000~40 000),冲击间距和冲击孔直径之比H/D(0.17~2.0),冲击孔和气膜孔间距与冲击孔直径之比P/D(0~5.0)等参数,利用热膜法研究了该典型冷却单元结构中内表面的换热特性。研究结果表明:参数Re,H/D,P/D对内表面局部换热系数的影响呈现出复杂的关联性。在本文的实验工况参数条件下,随着冲击Re数的增加,内表面换热效果逐步增强;并且存在一个最佳的H/D和P/D范围使得内表面换热效果最佳。综合分析实验结果,当H/D=0.67,P/D=3时,双层壳型冲击/气膜冷却结构内表面能达到最佳的换热效果。 |
关键词: 推进系统 喷射冲击 薄膜冷却 传热系数 |
DOI: |
分类号:V231.1 |
基金项目: |
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Experiment on local heat transfer coefficient of a double-decker jet impingement/gimm cooling structure |
MAO Jun-kui,LIU Zhen-xiong,GUO Wen,JIANG He-fu
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1.Coll.of Energy and Power,Nanjing Univ.of Aeronautics and Astronautics,Nanjing 210016,China;2.China Gas Turbine Establishment,chengdu 610500,China
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Abstract: |
Experiments were carried out to investigate the heat transfer coefficient on inner surface of a lamellar double-decker jet impingement/film structure.Impingement Reynolds number(10 000~40 000),the ratio of the jet impingement distance to the diameter of the jet hole H/D(0.17~2.0),the ratio of the distance between the jet hole and film hole to the diameter of the jet hole P/D(0~5.0)were changed to study the rules of local heat transfer coefficient varying with these parameters.All the results show impingement Reynolds number,H/D and P/D affected heat transfer on inner surface together and the rules are complex.In experiments,higher heat transfer coefficient was achieved under larger impingement Reynolds number conditions.And there exists a proper range of H/D and P/D,which can result in a maximum heat transfer coefficient.It is verified that when H/D=0.67 and P/D=3,the maximum heat transfer coefficient can be achieved. |
Key words: Propulsion system Jet impingement Film cooling Heat transfer coefficient |