Experimental investigation of the angle of attack dependence of the flow past a cactus-shaped cylinder with four ribs

The aerodynamic properties of a two-dimensional cactus-shaped cylinder with four ribs are studied experimentally. cross section the corresponds to modified square rounded corners and concave sides inspired by tall succulents ribs. mean coefficients, fluctuating lift coefficient, Strouhal number, surface pressure distribution measured as function angular orientation for Reynolds numbers ranging from 50,000 150,000. Hot-wire measurements conducted at two locations in wake several angles attack provide insight into vortex shedding frequencies. results show that shape exhibits strong angle dependence while no number is found within tested range. As cylinder, critical approximately 13° observed which drag forces minimised reach their highest values. Reattachment shear layer above confirmed using PIV. Overall, retain some benefits have been cylinders many ribs, albeit over limited range attack.