Investigation on the Performance of Forward Bending Fan

Abstract

Abstract The forward bending centrifugal fan features long vanes and narrow passages, and the internal flow is apt to be affected by wall boundary layer of the blade surfaces. An aerodynamic investigation on the forward bending centrifugal fan is presented in this paper. The performances of the unsteady flow field in the centrifugal fan is predicted by solving the incompressible Reynolds-averaged Navier-Stokes (RANS) equations based on the Shear Stress Transport (SST) – Scale Adaptive Simulation (SAS) turbulence model. And three-dimensional (3-D) flow phenomenon of non-uniform fluid flow is discussed through observing the flow separation and vortex distribution in the impeller region. The installation location of inlet nozzle is finally adjusted based on the calculated results, and the centrifugal fan with eccentric inlet nozzle is proposed. From the results, the eccentric inlet nozzle with L=3 mm, θ=120° could improve the internal flow of the forward bending centrifugal fan and enhance its aerodynamic performance.