An Investigation Into Unsteady Blade Forces in Turbomachines

Abstract

The wake interaction problem in a turbomachine has been simulated in a water table. The pressure distribution over a compressor blade during a passage of a wake shed by an upstream wake generator has been determined experimentally using specially developed piezoelectric pressure transducers. The thin airfoil-wake theory has been extended to cover the case of wakes of finite thickness. An attempt has been made to predict the pressure perturbation induced at the blade prior to the arrival of the wake due to the potential flow about an upstream blade. The effect of the distortion of the wake while on the blade is demonstrated; the difference between the computed and measured pressure perturbations indicates the need for taking account of this effect.