ON THE NOISE OF JET FROM A SMALL SCALE AXISYMMETRIC CONVERGENT NOZZLE IMPINGING ON A LARGE FLAT PLATE

Abstract

To understand the characteristics of the noise generated by impinging jet from a small-scale nozzle, the far field sound pressure level was studied. It was found that there was a critical pressure ratio according to different condition. Under this pressure ratio the noise intensity raised rapidly but wavily, and over this pressure ratio the noise intensity raised enhanced slowly but steadily with the increase of the pressure ratio. The critical pressure ratios will decrease when impinging gets oblique.