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一、引言 平行平板通道自然对流换热的数值求解常采用二维假设,用干涉法测量通道内气流温度场也是在二维场的前提下进行.然而,工程实际中所遇到的通道自然对流问题总会有端部效应存在.目前,可以说明二维假设的适用范围的实验结果很少.sparrow曾用质交换的方法研究了通道自然对流换热,并得出如下结论:如果(b/h)Ra大于10,则通道两端封闭与否对总换热量无多大影响,系统可看作是二维的.本文着重讨论端部效应对通道自然对流速度场的影响,试验研究了端部效应的强弱与通道几何尺寸和平板与环境的温差的相互关系.
I. INTRODUCTION Two-dimensional assumption is often used in the numerical solution of natural convective heat transfer in parallel plate channels. The interferometric method is also used to measure the temperature field of gas flow in the channel under the premise of two-dimensional field. However, At present, there are few experimental results on the applicability of the two-dimensional hypothesis.Sparrow has studied the natural convection heat transfer by the method of mass exchange, and concluded that if (b / h) Ra is greater than 10, then the closed or not at both ends of the channel has little effect on the total heat exchange, the system can be seen as two-dimensional.This paper focuses on the influence of the end effect on the natural convection velocity field, the experimental study of the end The relationship between the strength of the ministry effect and the channel geometry and the temperature difference between the tablet and the environment.