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Junwu Hong

Publications and source records attributed to Junwu Hong.

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Full-field prediction for engineering-scale three-dimensional aircraft with multigrid-hierarchical learning

High-fidelity computational fluid dynamics is essential for aerospace design, but engineering-scale simulations of practical three-dimensional aircraft remain computationally expensive. Learning-based flow-field initialization can improve efficiency by reducing the numerical distance between the initial and converged solutions, yet existing deep learning approaches remain difficult to scale to large three-dimensional aircraft flows with multiscale regional heterogeneity. Most prior studies therefore focus on two-dimensional problems, surface quantities, integral aerodynamic coefficients, or simplified three-dimensional cases with limited grid resolution.Here we propose MHLF, a multigrid-hierarchical learning framework for accelerating engineering-scale aircraft flow simulations while preserving high-fidelity numerical accuracy. MHLF combines a topologically consistent geometric multigrid representation with a hierarchical strategy that captures regional flow heterogeneity during both prediction and subsequent CFD correction. Across three engineering-scale aircraft cases spanning Mach 0.15 to 6.0 and covering subsonic, transonic and supersonic regimes, MHLF accelerates convergence without sacrificing flow-field accuracy, achieving a 3 to 8 times efficiency improvement over conventional initialization. These results demonstrate practical full-flow-field prediction for large three-dimensional aircraft within the CFD domain and provide a foundation for data-driven acceleration of high-fidelity aircraft flow simulation.

physics.flu-dyn

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.

physics.flu-dyn