旋转半受限单孔冲击局部换热特性实验

利用热膜法测量局部换热系数Nu,对旋转条件下半受限冲击射流的换热特性开展了实验研究.通过改变冲击雷诺数Re(20 00035 000)和旋转数Ro(00.003 441)等参数,讨论了旋转状态对半受限单孔冲击换热特性的影响.实验结果表明:旋转显著影响了冲击靶面的局部换热系数分布规律.在实验工况范围内,靶面局部(平均)Nu数均是先随着旋转数Ro的增加而增强,后又随着旋转数Ro的增加而减小.实验中还观察到同静止情况相似,旋转条件下半受限冲击射流的冷却效果也是随着冲击Re的增加而不断提高. 

Experimental investigations on the local heat transfer coefficient of rotating single circular impingement in a half-limited space

The local heat transfer coefficient Nu of rotating single circular impingement in a half-limited space was studied experimentally.Heated film and thermocouples were used to measure the temperature of target plate and the local heat transfer coefficient Nu was obtained.Jet Reynolds number(Re) of 20 000～35 000 and rotation number(Ro) of 0～0.003 441 were varied to study the heat transfer characteristic of impingement cooling applied under rotating condition.The results show that the Nu is affected greatly by rotation, and the distribution of Nu in rotating condition is quite different from that in stationary condition because of the centrifugal and coriolis forces.With Ro increasing, local and average Nu of target plate increases firstly and then decreases.And the Nu of single circular impingement increases with Re increasing, which is the same as that in stationary case.