Unstructured Method for Flows past Bodies in General Three-Dimensional Relative Motion

Abstract

A three-dimensional methodology was developed for unsteady e ows past bodies that are in relative motion and where the trajectory of the motion was determined from the instantaneous aerodynamic e eld. This method coupled the equations of e uid e ow and those of rigid-body dynamics and then captured the unsteady aerodynamic interference between the stationary and moving boundaries. The time-dependent, compressible Euler equations weresolvedondynamic,unstructuredmeshesbyanexplicit,e nitevolume,andupwindmethod.Thegridadaptation was performed within a window placed around a moving body. The Euler equations of dynamics were then solved by a Runge‐Kutta integration scheme. The e ow solver and the adaptation scheme were validated by simulating the transonic, unsteady e ow around a wing undergoing a forced, periodic pitching motion and then comparing the results with the experimental data. Finally, the overall methodology was demonstrated by simulating the unsteady e owe eld and the trajectory of a store dropped from a wing. The methodology, with its computational cost notwithstanding, has proven to be accurate, automated, easy for dynamic gridding, and relatively efe cient for the required work hours. Nomenclature at