Simulation of the Influence of Aspect Ratio on the Aerodynamics of Rectangular Prisms

Abstract

A numerical simulation of three-dimensional flow around rectangular prisms (two dimensional) of different aspect ratios, ranging from 0.3 to 7.0, is conducted at a Reynolds number of 105, using large eddy simulation. This study identifies the influence of aspect ratio on the flow field around prisms and the attendant aerodynamics. Results show salient features in the flow field and associated pressure/aerodynamic forces caused by changes in the afterbody, which demonstrate good agreement with observations from wind tunnel experiments. A time-frequency analysis is introduced to identify the transient nature of fluctuations in the drag and lift coefficients, highlighting temporal variations in the frequency contents of these fluctuations and their resulting influence on force coefficients.