Numerical study on characteristics of sound and wake generated by flow past triangular cylinder at various incident angles

Abstract

Characteristics of sound and wake generated by flow past a triangular cylinder with Mach number 0.3 at various incident angles are studied by numerically solving the compressible Navier-Stokes equations using OpenFOAM. The Reynolds number in this study is varied from 140 to 180. Vortex streets behind the cylinder are observed to have different patterns as the Reynolds number and the angle of incidence are varied. The mean lift coefficient has zero value when the cylinder is symmetric and maximum value at incident angle approximately 30◦. The mean drag coefficient is observed varying when incident angle increaes. The Strouhal number observed has the value in the range of 0.15−0.21. Sound is generated mainly from a fluctuation in the lift and drag forces due to the shedding of vortices. The frequency of sound in far field is observed shifting when the incident angles is increased because of the different behavior of the fluctuating lift and drag forces.