Vortex Shedding in the Wake Region of a Cylinder

Abstract

During flow past a blunt body, such as a circular cylinder, usually experiences boundary layer separation and very strong flow oscillations in the wake region behind the body. In certain Reynolds number range, a periodic flow motion will develop in the wake as a result of boundary layer vortices being shed alternatively from either side of the cylinder. It creates an oscillating flow at a discrete frequency that is correlated to the Reynolds number of the flow. The objective of this project work is to plot the relations between frequency of vortex shedding and Reynold’s number as well as Strouhal’s number and Reynold’s number. A 2-D model is constructed using GAMBIT and transported to FLUENT, where it is simulated in unsteady state. An animation movie is made by capturing glimpses of the flow field at periodic intervals. Later, this movie is played to manually determine frequency of vortex shedding.