圆形自由射流冲击任意热流密度平板时的换热分析

Analytical Study of Heat Transfer with Single Circular Free Jets under Arbitrary-heat-flux Conditions

对射流冲击平板时的层流运动给出了速度和温度边界层的综合划分,用积分方法得到了小P_r数下等热流平板和高P_r数下任意热流平板的驻点区流动换热关系式,在部分壁面射流区,利用Mangler变换技巧,得到任意热流平板的换热系数,并以等热流平板作为特例,与精确解和数值解作了比较,都具有较好的一致性。

Analytical research was conducted to study heat transfer from horizontal surfaces to normally impinging circular jets under arbitrary-heat-f lux conditions.The thermal and laminar velocity boundary layers were first divided into five regions of flow in a comprehensive method.Approximate expressions of heat transfer coefficient were obtained both for stagnation zone and partial wall jet zone by applying integral techniques and Mangier transition.The analytical results of the constant-heat-flux condition agree with those of both of the exact solution and numerical solution from available literature