Effects of Temperature on Acoustic Waves in Supersonic Jet at Mach 2.0

Abstract

Strong acoustic waves are generated from the rocket plumes in the supersonic jet condition. The acoustic waves are significantly affected by temperature of jets. In this study, we perform large eddy simulations of the hot and cold jets that generate the acoustic waves. The temperature ratio of chamber to ambient air is set to be 4.0 and 1.0 for the hot and cold jets, respectively. High frequency Mach waves are radiated from the region close to the nozzle exit. As closer to the potential core, the frequency of radiated Mach waves continuously becomes low. In the hot jet case, we confirmed that the shorter potential core length, the larger angle of Mach waves, and the higher sound pressure level, as compared with those in the cold jet case.