Large-amplitude fluctuations of velocity and incidence of an oscillating airfoil

Abstract

unsteady problem (uz ) 0 and ( vz ) 0 oscillate about their steady values and appear to be exactly one-quarter period out of phase. This is also the case for w(oo,7) and D. A phase change in the skin-friction components occurred in a problem also considered by Homsy and Hudson: they analytically investigated the unsteady development of almost solid-body rotation, i.e., s=l-e, l e l ^ l . It can be shown from their results that the departures of (uz)0 and (v,)0 from their s steady values are ( T r T 3 7 2 ) ~ ecos2Tand (4^J^^T ) ~ l esin 2T, respectively, i.e., a phase difference of ir/4. It is hoped that the results of other investigations will be published in the near future.