人工压缩法数值模拟非定常不可压缩热对流流场

Numerical simulation for unsteady incompressible thermoconvective flow with artificial compressibility method

利用人工压缩方法数值模拟了由于强热浮力不稳定性引起的非定常不可压缩热对流流场．在非定常动量、能量方程中引入了一伪时间项，连续性方程中加入与伪时间层相关的人工压缩项，使连续性方程与动量方程自动耦合，得到一沿物理时间准确推进的沿伪时间层采用ＧａｕｓｓＳｉｄｌｅ内迭代的推进迭代算法．在每一时间层进行内迭代直到连续性方程满足为止．对流项用四阶中心差分格式，时间项用三阶向后差分．利用此算法数值研究了二维ＰｏｉｓｅｕｉｌｅＢｅｎａｒｄ流场和底部加热的非定常水平射流问题，成功地模拟了流场中涡旋的生成及发展过程．结果表明。

Two unsteady incompressible flows resulting from strong thermoconvective instability are simulated with artificial compressibility method.A pseudotime term is added both in unsteady momentum and energy equations while a artificial compressibility term is added in continuity equation .Subiterations in pseudotime are used to satisfy the continuity equation at each physical time step.The Gauss Sidle iterating method is used in subiteration.Fourth order center differencing schemes are used to compute the convective fluxes.Third order backward differencing scheme is used to compute the physical time term.2 D unsteady Poiseuille Benard flow and horizontal jet in a stratified fluid flow are simulated with this method.The creating and propagating of eddies in flow are successfully captured.The efficiency and accuracy of present method for simulating unsteady thermoconvective flow are indicated clearly in our results.