Turbulent flow topology optimization in nuclear reactor pressure vessel via NURBS-based particle hydrodynamics (NBPH) topology optimization framework.

In this article, we focus on a design problem of flow distribution structure in nuclear reactor pressure vessel within the meshless topology optimization framework. A novel meshless particle method, NURBS-based particle hydrodynamics (NBPH) method, is proposed. And a meshless CFD computational model based on NBPH is presented to analyze the coolant flow field in pressure vessel. Comparing the results of NBPH with those of FVM in Fluent, we conclude that the proposed method can not only obtain physical field solution with high accuracy, but also has high computational efficiency. By coupling the NBPH method with the solid isotropic material with penalization (SIMP) method, a unique NBPH-TO structure design platform is constructed, in which the communication between the meshless solver and the mesh-based optimizer is accomplished by solving the transient sensitivities and constructing a voxel-based friction field. Two structure designs with opposite flow distribution objectives are investigated in the paper to demonstrate the effectiveness and robustness of the NBPH-TO structure design platform. The design cases show that the constructed NBPH-TO framework can obtain the optimal topology stably. This is the first attempt to apply the meshless topology optimization method to the design of the internal structure of the lower chamber of a pressure vessel. The research provides a viable solution and an effective tool for design of structures within nuclear reactor pressure vessels. [ABSTRACT FROM AUTHOR]