含内热源的梯形腔自然对流换热数值模拟

Numerical simulation of natural convection in trapezoidal enclosures with discrete heater

引言 封闭腔体内的自然对流换热问题在实际工程中有着重要应用，因而受到越来越多的关注，工程实际中常用的腔体结构有方腔、圆形腔、三角形腔等。考虑到工程实际，较为复杂的梯形腔也成为研究热点：Karyakin对二维等腰梯形腔内自然对流问题进行了研究，

A numerical study is carried out on natural convection in a two-dimensional trapezoidal enclosure with a centered discrete heater.For a fixed area discrete heater,in the range of aspect ratio ε from 1 to 6,rotation angle θ from 0° to 90°,and Rayleigh number from 103 to 106,the changes of isotherms,streamlines and Nuave in the trapezoidal enclosure are studied.The simulation results show that heat transfer mechanism in the trapezoidal enclosure changes from conduction to convection as Ra increases,and Nuave increases simultaneously.The variations of ε and θ also have great effect on the heat transfer in the enclosure,and the increase of ε has a positive effect on the heat transfer.Nuave reaches the maximum or minimum value at different values of Ra and ε.