模拟无粘超音速射流/绕流干扰的高分辨率自适应网格数值方法

AN ADAPTIVE GRID EMBEDDING TECHNIQUE WITH HIGH RESOLUTION FOR NUMERICAL SIMULATION OF INVISCID SUPERSONIC JET/EXTERNAL-FLOW INTERACTIONS

本文提出一种模拟飞行器超音速尾喷流与飞行器超音速绕流相互作用所形成的复杂流场的差分方法。本方法对流场中的光滑区域使用传统的二阶格式,而在流动参量变化剧烈的区域中采用细网格的、具有高分辨率的TVD格式。为此,文中设计了一种逐维自适应网格加密技术,并与Strang型分裂格式相结合,以求解多维的气体动力学方程。作为算例,本文给出了以Euler方程为模型的尾喷流/绕流干扰流动的计算结果。数值计算表明,本文所提出的自适应网格加密及局部使用TVD格式的算法不仅可以取得高清晰度的流场显示,同时还可使整个计算的效率得到大幅度提高。

A procedure based on an adaptive grid embedding technique is proposed in the present paper to simulate the complex flow fields induced by the interactions between supersonic jets and external flows. The proposed procedure utilizes the high- resolution TVD scheme for solving the local flow field where flow parameters are found to vary drastically, and any conventional second-order scheme can be used to solve the problem in the remaining region. To serve the purpose, a single-dimensionally adapting technique is developed and applied successively, in conjunction with the Strang-type splitting scheme, to solve the multi-dimensional gas dynamic equations.As a demonstration, solutions of the Euler equations for a flow of supersonic jet interacting with an external flow computed using the adaptive grid technique developed in this work, as well as the conventional TVD procedure, are presented in this paper. The numerical results reveal that the present technique is capable of providing visualizations of complex flow fields with high resolution. Yet, through comparisons, it is also found to be highly efficient.