Abstract: Computational fluid dynamics (CFD) simulation is an important method for optimization and research of multi blade centrifugal fan. The details of geometric processing in the rotation domain of the fan, mesh types, etc. will have a certain impact on the CFD simulation results. Firstly, divide the same impeller into different meshes, and calculate the impact of different mesh conditions on the CFD calculation results. The mesh conditions mainly include different mesh types: hexahedral, hybrid, mesh with and without boundary layer, and whether the rotation domain is expanded. Then, a case was presented to analyze the error in simulation results. The results show that, the non-refined boundary layer mesh and the expansion of the rotation domain will lead to the deviation of the simulation results. After the multi blade centrifugal fan model in this research case is modified, the maximum difference between the simulation results and the measured results is reduced from 4.40% to 0.73%. The research is of great significance to improve the accuracy of multi blade centrifugal fan simulation.

Key words: Multi blade centrifugal fan, Rotation domain, Mesh type, Boundary layer, CFD