Erosion of a polystyrene bed by obliquely impinging circular turbulent air jets

This paper presents the results of an experimental study of the erosion of a cohesionless bed by obliquely impinging circular turbulent jets. The jet of air, with velocity of 27.3 to 86.8 m/s and diameter at the nozzle of either 6.35 or 12.6 mm, was set to impinge on a bed of polystyrene particles at varying angles of impingement of 7.5 to 60. Several characteristic dimensions of the scour hole were measured and analyzed and found to depend on the angle of impingement and the erosion parameter F-o/(H/d), where F-o is the densimetric Froude number, H is the impingement distance, and d is the diameter of the jet at the nozzle. Correlations were developed for the main characteristics of erosion at asymptotic state. Observations of the growth of the scour hole are also presented.