Simulation of a Centrifugal Pump Based on a Lagrangian Particle Solver

Abstract

A three-dimensional full-scale centrifugal pump is simulated using the moving particle semi-implicit (MPS) method. The generic smoothed wall (GSW) boundary is used and extended to three dimensions to address complicated wall shapes and thin-walled structures such as blades in turbomachines. The nonsurface detection technique (NSD) based on conceptual particles is introduced to avoid the loss of the particle-number-density near wall boundaries. A generic approach that can transfer arbitrary CAD models to wall-particle models is established by utilizing the nodal information of the shell mesh. An adaptative resolution technique is proposed by using fine and coarse particles to model the wall boundary with complex geometry. Fine and coarse particles are applied to curved and flat surfaces, respectively, to reduce the computational cost while maintaining high discretizing precision. A criterion based on the normal smooth angle (NSA) is defined to evaluate the local or global precision of established models and provide instructions for refinement. A fully-developed velocity inflow boundary based on 3D inlet rings and pressure outflow boundary based on the moving virtual wall is implemented. Three typical cases including hydrostatic cases with a typical geometry, flow over a two-dimensional backward-facing step, and flow over a three-dimensional tube are tested to verify the proposed models. A particle-based framework to simulate incompressible fluid machines, in which flow fields can be integrally discretized and solved within a single coordinate system, is established. The results are compared with those of the fine volume method and satisfactory agreements are observed.