Experimental investigation of turbulent flow past four grooved and smooth cylinders in an in-line square arrangement

Abstract

An experimental study of turbulent flow past four cylinders in square arrangement with a space ratio of (T/D = P/D = 2.88) is performed. The investigation focuses on effects of Reynolds number and the shape of cylinders on the force and pressure coefficients of the cylinders. Two cases are investigated: four smooth cylinders (case1) and four grooved cylinders (case2). The cylinders are equipped with two grooves placed on the external surface at 90° and 270° degrees. The pressure distributions along the tubes (22 circumferential pressure taping) were determined for a variation of the azimuthal angle from 0 to 360deg. The drag and lift forces are measured using the TE 44 balance. The results show a bistable flow often exists behind the downstream cylinders is observed. By rising the Reynolds number the pressure coefficient increases in the absolute value.