Numerical Study of Laminar, Transitional and Turbulent Flow Past Rectangular Cylinders

The subject of flow past slender bluff bodies is of relevance to technical problems associated with energy conservation, structural design and acoustic emissions. The present work is restricted to an important sub-class of slender bluff body flow --- the incompressible flow around a stationary cylinder having a rectangular cross section, the cylinder being exposed to a constant free stream velocity. Time-dependent two- and three-dimensional (2D/3D-) numerical simulations are carried out. Some useful quantities such as the dominant wake frequency (the Strouhal number), mean and RMS values of drag and lift, and various surface pressures etc. were calculated for different Reynolds numbers. In 2D-simulations, the effects of cylinder side ratio (B/A, where B is the longest side) and flow incidence (.alpha.) were investigated. In these simulations an incompressible non-staggered arrangement SIMPLEC code was used. The QUICK and Van Leer schemes were used for the convective terms. The time discretization was implicit and a second-order Crank-Nicolson scheme was employed. The influence of Reynolds number (R