基于BDF2-AB2的钢铸件凝固多物理场耦合模拟方法OA

Numerical simulation of the solidification process of steel castings plays a crucial role in defect prediction and process optimization.However,the strong nonlinearity of the governing equations poses significant challenges to the stability and efficiency of numerical algorithms.This study proposes a multiphysics coupled solution method based on the BDF2-AB2 hybrid time integration scheme,provides a detailed introduction to the establishment of mathematical models and numerical discretization methods,and compares it with the classical explicit Euler method.The results show that,under comparable mesh resolutions,the computational cost per time step of BDF2-AB2 method is similar to that of the explicit Euler method,and exhibits a significant advantage in numerical stability.The explicit Euler method becomes unstable when the time step increases to 0.000 5 s,while the BDF2-AB2 scheme shows numerical stability until the time step reaches 0.01 s,with a maximum stable time step approximately 20 times larger than that of the explicit Euler method.In engineering applications,the proposed BDF2-AB2 method can successfully capture the solidification process and macro segregation behavior of three-dimensional steel ingots,and provide an efficient and reliable computational framework for high-fidelity numerical simulation of casting solidification processes.