OpenFOAM Application on Performance Predictions of an Industrial Centrifugal Fan with Airfoil Blades

Application of Analytical, Computational and Experimental Methods

Computational fluid dynamics (CFD) has increasingly been applied to industrial fan design over the past decade. The high-performance computation for CFD has become more accessible as the cost of computer hardware has been cheaper. The well-known finite volume CFD solver, OpenFOAM widely used in schools is gradually being a favourite approach by industrial fan designers for predicting the performance of industrial fans for it is fully open-sourced and no limitations are on the parallel computation. This paper presents a modelling approach of an airfoil bladed centrifugal fan which we developed for performance predictions of our regular industrial products. In the model, the snappyhexmesh tool is applied to create the hexahedral dominant mesh with boundary layers on the fan wall surfaces. The multiple reference frame (MRF) model is employed for the simulation of rotation zone. The Spalart-Allmaras model and k-ω Shear Stress Transport (SST) model are used for the turbulence flow for a comparison purpose. The OpenFOAM allrun template for fan performance predictions are developed. The parallel computation setup and postprocessing programing are also presented in the paper. The results of fan pressure, power, and efficiency using the two turbulence models are compared and discussed and the future development on the CFD model is recommended.

Keywords: Industrial centrifugal fan, Fan performance prediction, Open source solver, CFD