Calculations of generalised airforces on two parallel lifting surfaces oscillating harmonically in subsonic flow

Abstract

Two flat parallel surfaces, oscillating harmonically about a mean configuration are immersed in a uniform subsonic main stream in a direction parallel to the surfaces. The linearised equations of potential flow are assumed to be valid, so that the upwash on the surfaces can be related to the loading on the surfaces by means of a pair of integral equations. This pair of integral equations is solved, by collocation, for approximations to the loadings in terms of given upwashes and these approximations are used to evaluate generalised airforces. The results are compared with some results obtained by other numerical procedures and with some experimental results. The procedure has been programmed in 1900 FORTRAN.