首页
>
西北工业大学学报 >
2016年1期 > 非定常求解的内迭代初值对计算效率的影响研究
非定常求解的内迭代初值对计算效率的影响研究
Researching how Initial Value of Internal Iteration Impacts on Computational Efficiency in Unsteady Flow Solving
2016年2月28日
【正式出版版本】
【曾经优先出版版本】
Researching how Initial Value of Internal Iteration Impacts on Computational Efficiency in Unsteady Flow Solving
- doi:
- 10.3969/j.issn.1000-2758.2016.01.002
-
摘要:
-
基于非定常流场的双时间求解方法,提出了一种提高非定常流场求解效率的有效策略。通过对前几个时刻的流场信息进行外插来确定下一时刻的迭代初值,使之更接近于收敛解,降低内迭代初始残值,进而提高了非定常流场的求解效率。将流场中每个点的守恒量在时间方向上进行泰勒级数展开,设计了若干种外插格式。采用绕圆柱非定常流动的求解来验证本方法的计算效果,并研究了不同初值外插格式、空间离散格式、时间步长和收敛标准对初值外插方法效果的影响。研究表明,在双时间步法基础上,采用初值外插策略可普遍提高计算效率,其中交替外插策略可以普遍将求解效率提高1倍左右。相比于迎风格式,该方法对中心格式的求解效率提高更显著,并且对于不同的收敛标准和时间步数均有非常明显的效果。
-
Abstract:
-
On the basis of the dual time stepping method in unsteady flow, we come up with a strategy to improve the efficiency in unsteady flow solving. By means of extrapolating the flow message of a few moments forward, we get the iterative initial value of the next moment to make it closer to the convergent solution and decrease the initial residual value of internal iteration, thus increasing the computational efficiency of unsteady flow. Taylor expand the convective term of flow field in time direction, then we design some kinds of extrapolation schemes. We use the so?lution of unsteady flow around circular cylinder to verify the computational efficiency of this method, and research on different initial value extrapolation schemes, spatial discretization schemes, and time steps and convergence cri?teria impacting on the efficiency of initial value extrapolation method. Researches show that based on the dual time stepping method, using the strategy of initial value extrapolation can improve the computational efficiency generally. Of which the alternate extrapolation strategy can doubled the efficiency generally. Compared with upwind scheme, the efficiency of this method increases more when using center scheme;all have obvious effects when using different time steps and convergence criteria.
参考文献和引证文献