Estimation of performance of prototype axial flow fan from model test

Abstract

Scale formulae have been derived for the prediction of the performance of prototype fans from model tests for the prerotator-rotor and rotor-straightener type units based on the aerofoil characteristics of RAF 6-series which are available over a wide range of Reynolds number. Suitable formulae have also been derived for predicting the shift of the point of maximum efficiency towards the higher flow coefficient as the size of the prototype is increased. As assumptions have been kept to the minimum it is hoped that this method would be more realistic than any of the existing methods. The agreement between the prediction of the prototype from the formulae and the result of the prototype has been quite fair.