Hierarchical Iterative Method in CFD Numerical Solution

We propose a hierarchical asynchronous iterative method that differs from the traditional synchronous iterative method used across the entire flow field in conventional Computational Fluid Dynamics applications. This method forcibly divides the spatial region of the flow field into three layers: the boundary layer, the inner field, and the outer field. By adopting a novel approach of using different iteration steps for each layer, it significantly enhances computational efficiency. Using the hierarchical iterative method, numerical simulation studies were conducted on three typical benchmark models with different velocity ranges. Additionally, discussions were held regarding new modes such as using different control equations and computational parameters for each layer. The results based on structured grids indicate that, for the cases studied in this paper, the proposed method can achieve identical simulation results compared to traditional methods while only consuming 53.2% of the computational time of traditional methods, without significantly increasing manpower costs. This paper provides suggestions and discusses on the numerical applications of this novel iterative mode, and offers new insights for follow-up research based on this method.