一种改进的非定常激波装配算法

An improved unsteady shock-fitting algorithm

基于非结构动网格技术和格心型有限体积方法,提出一种改进的非定常激波装配算法,进一步拓展了其在包含有运动激波的非定常流场的应用范围。首先,针对激波在直/曲壁面传播这类问题,分别建立了壁面间断节点的运动模型;其次,为保证激波在大范围运动时装配阵面不产生失真,基于Bézier曲线拟合方法实现了间断节点分布的自动重构;接着,通过嵌入局部网格自动重构模块,提高了算法的计算效率和自动化程度;最后,对于激波相交点的运动,设计了一种根据位移推算速度的方法进行装配。数值算例表明,所提算法能够有效地处理激波传播问题,相比激波捕捉方法可以提取更多的流场信息,同时可以获得流场间断更加直观清晰的图谱。

Based on the unstructured dynamic grids technique and the cell-centered finite volume method,an improved unsteady shock-fitting algorithm is proposed to deal with unsteady flow containing moving shock waves.First,for the problem of shock wave propagating along the straight/curved wall,the motion models of wall discontinuity nodes are built respectively.Second,automatically distributing the discontinuity nodes on the basic of Bézier curve fitting method is realized to ensure fitted shock wave fronts move in a wide range without distortion.Then,by embedding the local module with automatic remeshing,the efficiency and automation of the algorithm are significantly improved.Finally,for the motion of shock wave intersection point,a method of calculating velocity vector using displacement is designed to yield a fitting solution.Several simulation results show that the proposed algorithm can effectively deal with shock wave propagation problem.Compared with the shock-capturing method,the proposed method can extract much more flow field information and obtain a more straightforward and clearer map of flow field discontinuity.