The development of a computer code (U2DIIF)--for the numerical solution of unsteady

Abstract

A numerical technique is formulated, in a computer program U2DIIF, for the solution of flow over an airfoil executing an arbitrary unsteady motion in an inviscid and incompressible medium. The technique extends the well known Panel Methods for steady flow into solving a non-linear unsteady flow problem arising from the continuous vortex shedding into the trailing wake due to the unsteady motion of the airfoil. Numerous case-runs are presented to verify U2DIIF computer code against other theoretical and/or numerical methods as well as in cases where limited experimental data are obtainable in literatures. These case-runs include airfoils undergoing a step change or a modified ramp change of angle-of-attack, airfoils executing harmonic oscillation in pitching and plunging motions and airfoils penetrating a sharp edge gust. (Author)