Experimental study for the cross-flow around three cylinders in an isosceles right triangle configuration

Abstract

Wind tunnel experiments were conducted to measure the pressure distributions for three circular cylinders, with equal diameters, in an isosceles right triangle arrangement when subjected to a cross-flow. The pitch ratio P/D was fixed at 2.3.5 angles of incidence ranging from 0° to 315° that covered all orientations were investigated. Both smooth (low-turbulence) and turbulent inflows were employed. These experiments were carried out at 5 Reynolds numbers ranging from 2.1 × 105 to 6.2 × 105 when the incoming flow was smooth. For turbulent inflows, 7% and 16% turbulent intensities were used. Under the same turbulent intensities, two mean wind speeds (10 m/s and 15 m/s) were employed. The pressure distributions on the surface of each individual cylinder were measured using pressure transducers. Besides, four pressure distribution patterns over the cylinders were defined. Then, the differences between the pressure distributions over the cylinders in the subcritical and supercritical regimes were discussed. Furthermore, the relationships between pressure distributions in turbulent and smooth inflows were investigated. The aerodynamic force coefficients were also presented in this paper, and the classical Reynolds number effect was observed.