Experiment of Supersonic Jet Noise from a Laval Nozzle

Abstract

The characteristics of supersonic jet noise from a Mach 2.0 nozzle with a thin-nozzle-lip thickness have been experimentally studied over a range of nozzle pressure ratios from 2.0 to 10.0. Acoustic measurements were conducted in an anechoic room providing a free-field environment. Shadowgraph technique was used as the tool to study qualitatively the shock wave patterns which are primarily responsible for shock related noise. The measured screech frequencies under overexpanded conditions are found to agree with Tam's theoretical results.