Influence of Grid Resolution on Flow Field and Aerodynamic Noise Prediction of Centrifugal Fan for Packaged Air Conditioner

Abstract

In this study we calculated flow fields and aerodynamic noise in centrifugal fan of air conditioner by large eddy simulation (LES). The numerical simulation code employed throughout the LES was FrontFlow/blue (FFB). We compared calculation results for 10 million grids (10M-grid), 60 million grids (60M-grid) and 500 million grids (500M-grid) to investigate the influence of grid resolution on the prediction accuracy. The prediction accuracy of the aerodynamic noise by the 500M-grid was improved compared to the 10M-grid and 60M-grid calculation results. The grid resolutions between the shroud and the bell mouth and between one blade and an adjacent blade were important. Moreover, we found the proper capturing of the streaks contributed to better prediction.