竖环形夹层内自然对流换热的实验研究和数值计算

EAPERIMENTAL AND NUMERICAL INVESTIGATIONS OF NATURAL CONVECTION IN VERTICAL ANNULI

作者对两端封闭且绝热、外管表面为等温边界条件、内管表面为不同热边界条件下的竖环形夹层内的自然对流换热进行了数值计算和部分实验研究。在实验模型中,加热管内表面维持为等热流边界条件。文中对四种加热管的边界条件进行了数值计算,给出了实验研究与数值计算的结果,分析了不同边界条件对于换热及加热管壁面温度分布的影响。在耦合问题的数值计算中,采用了双块修正技术,保证了迭代计算的收敛性。数值计算的结果同前人的研究和本文的实验结果的符合程度是令人满意的。

An investigation of natural convection of air in vertical annuli is carried out both numerically and experimentally.In the experiment,the outside surface of the annulus is kept at constant temperature,and the inner surface of the inner tube is heated with constant heat flux.The top and bottom surfaces are adia- batis.Numerical simulations are performed under four different thermal boun- dary conditions of the inner tube,one of which is of conjugated type.Double block correction technique is used to help bring about convergence of iterations in the conjugated case.The agreement between the experimental and numerical results is satisfactorily.In this paper,the results of experiments and numerical simulations are presented,and the effects of the different thermal boundary conditions on heat transfer and temperature distribution are analyzed.