Fluid–Structure Interaction of an Elastically Mounted Slender Body at High Incidence

Abstract

A numerical study of the fluid–structure interaction of an inclined tangent ogive-cylinder rigid body, mounted on torsion springs that can rotate in the pitching, yawing, and rolling directions, is conducted. The body is subjected to three-dimensional compressible laminar flow at a Reynolds number of 30,000 and a Mach number of 0.2. A second-order implicit finite difference scheme is employed for the flow equations, adapted to a curvilinear coordinate system, whereas the coupled structural equations, written using an Euler angle notation, are solved by a fourth-order Runge–Kutta method. A detailed investigation of two angles of attack, and , is described. For a fixed body at , the yaw moment changed smoothly with the location of the circumferential disturbance, whereas at the yaw moment was characterized by an almost square-wave variation behavior with bifurcation points at disturbance circumferential roll angles , , and . For an elastically mounted body, the response at for all disturbance locations resulted in large-amplitude periodic yawing and pitching moments. The response at resulted in large-amplitude moments, which occurred only for disturbance locations that coincided with the bifurcation points of the fixed body. The response at the bifurcation points was found to be quasi-periodic for , periodic for , and nonstationary for .