利用FFT高效求解二维瑞利-贝纳德热对流  

AN EFFICIENT SOLUTION FOR 2D RAYLEIGH--B′ENARD CONVECTION USING FFT

作　　者：徐炜[1] 包芸[1] 

机构地区：[1]中山大学力学系,广州510275

出　　处：《力学学报》2013年第5期666-671,共6页Chinese Journal of Theoretical and Applied Mechanics

摘　　要：研究提高二维方腔瑞利-贝纳德对流直接数值模拟求解方法的计算效率问题.对于非定常湍流热对流,压力泊松方程的求解是影响整个计算效率的关键.利用快速傅里叶变换(fast Fourier transform,FFT)解耦并结合追赶法,可实现压力泊松方程的直接求解.通过与跳点超松弛迭代法在求解精度和计算速度对比,可以看到,利用FFT压力泊松方程直接方法计算热对流问题是高效的.还给出了典型状态的热对流初始羽流和大尺度环流温度场,以及系列瑞利数(Ra)计算结果的宏观传热努塞数(Nu)变化.The computation efficiency of direct numerical simulation （DNS） for Rayleigh-Benard （RB） convection in rectangular containers is studied. For unsteady flow of RB convection, the solution of pressure Poisson＇s equation is a key issue affecting the computation efficiency in the whole solving process. Combined with fast Fourier transform （FFT） and chase method, a direct solution of pressure Poisson＇s equation is presented. Comparing the precision and speed with hopscotch overrelaxation iteration, it is found that the direct solution of pressure poisson equation for RB convection using FFT is efficient. The results of temperature fields for the plume and the large scale circulation, and the change of Nu number for series Ra numbers are given.

关 键 词：瑞利-贝纳德对流 快速傅里叶变换 泊松方程直接求解 直接数值模拟 

分 类 号：O357.5[理学—流体力学]