A numerical investigation of the dual performance characteristics of a small propeller fan using viscous flow calculations

Dual performance characteristics of a small propeller fan are numerically i nvestigated using: viscous flow calculations, A performance test of the fan showed dual performance characteristics, i.e, radial type characteristics at low flow rates and axial type characteristics at high flow rates, The pr esent work is aimed at investigating a sharp variation in the performance c haracteristics at low flow rates. The finite volume method is used to solve the continuity and Navier-Stokes equations in the flow domain around the f an. The performance parameters obtained from the calculations are compared with the measured values for the various flow rates. Comparisons between th e predictions and the measurements indicate that the predicted results are in good agreement with the measured values and reasonably reproduce the sha rp variations of the performance parameters at low flow rates. These compar isons show that the present numerical method is capable of resolving the pe rformance characteristics with reasonable accuracy, at low flow rates, it h as been found that the flow enters the fan in an axial direction and is dis charged radially outward at the tip, which is much like the flow characteri stics of a centrifugal fan. The centrifugal effect at low flow rates makes a significant difference in the performance characteristics of the fan. (C) 1999 Elsevier Science Ltd, All rights reserved.