NUMERICAL ANALYSIS ON STROUHAL FREQUENCIES IN VORTEX SHEDDING OVER SQUARE CYLINDERS WITH SURFACE SUCTION AND BLOWING

The effects of normal surface suction and blowing on the Strouhal frequencies in vortex shedding over porous square cylinders was analysed numerically. The general characteristics determined were (1) an initial increase followed by a decreasing behaviour in the Strouhal frequency with increasing suction velocity and (2) a decrease in the Strouhal frequency with increasing blowing velocity. The numerical results were compared to an existing preliminary model, yielding fairly close agreement.