Unsteady Forces on a Body Immersed in a Viscous Fluid : 3rd Report, For an Inclined Thin Elliptic Cylinder

Abstract

This paper considered a flow normal to an infinite thin elliptic cylinder which is uniformly accelerated from rest in a direction perpendicular to its generating lines in a viscous fluid. The Dufort-Frankel method for vorticity transport equation is used for the numerical simulation of viscous incompressible flows, and a new finite Fourier transform method is introduced in order to handle the stream function equation for accurate and efficient calculation. A major part of the present paper is devoted to physical properties of the flow during the early stages of wake developement behind an obstacle, for a Reynolds number of 98.11. A computer-aided flow visualization technique is used to demonstrate the main features of the hydrodynamic field for the flow. The rest of this paper demonstrates the important unsteady forces such as time-dependent drag, lift and moment acting on a body immersed in a viscous fluid, and presents specific numerical results for various transitions.