The performance of an aerofoil in stationary and rotating cascades

Abstract

A series of experiments have been performed with a rotating cascade wind tunnel to determine the effect of a rotational flow on the behaviour of the blades in a turbomachine. A two-bladed rotor has been tested as a stationary annular cascade - and also when rotating synchronously with a solid body rotational flow. It is then possible to make a direct comparison between the behaviour of the same blade in irrotational and rotational flows. It is shown that if the level of turbulence is greater than some critical value, then there is no significant difference in the unstalled performance of the blades in the stationary and rotating cascades. However, even at a relatively high level of turbulence, there is a marked difference in the manner in which the blade stalls for the stationary and rotating cascades.