复杂多孔介质腔体内自然对流换热的数值研究

采用曲线坐标系下压力与速度耦合的SIMPLEC算法,数值研究复杂多孔介质腔体内的自然对流换热问题.腔体的曲面温度分别保持恒定,上下表面绝热.在曲线坐标系中用有限容积法离散方程,并采用Brinkman扩展达西模型及局部非热平衡模型求解,综合研究Rayleigh数,Darcy数、孔隙率等参数对腔体内自然对流换热的影响.计算结果表明:Rayleigh数和Darcy数的影响最大而孔隙率的影响很小,同时存在使得腔体内换热达到最强的最佳纵横比.

Natural Convection in a Wavy Enclosure Filled with Porous Media

We study heat transfer and fluid flow in a complex enclosure filled with porous media,with SIMPLEC(Semi-Implicit Method for Pressure Linked Equations Consistent) algorithm in curvilinear coordinates.The upper and lower walls of the enclosure are horizontal and adiabatic.The vertical wall forms cosine curve and is kept at a constant temperature.Governing equations are discretized with a finite-volume method on body-fitted collocated grids.Brinkman-extended-Darcy model and local thermal non-equilibrium model are used to solve momentum and energy equations.Effects of parameters,such as Rayleigh numbers,Darcy numbers and porosity,on heat transfer and fluid flow are studied.It is shown that Rayleigh numbers and Darcy numbers have significant effect while porosity is negligible.There exists an optimal aspect ratio to make the heat transfer rate maximum.