Visualization of Density Fluctuation Distribution of a Supersonic Jet Using the Optical CT Method

摘要

By use of schlieren optics and microphones, jet noise sources of a rectangular hypersonic nozzle are investigated experimentally. Tomographic reconstruction of density fluctuation distribution of the jet and the cross-correlation analysis between the schlieren optics and the microphones are carried out. Maximum cross-correlation distributions show that the sound wave is highly directional within the downstream cone angle. In order to discuss the intensity of noise sources, the amplitude of the light intensity fluctuation and the maximum cross-correlations are multiplied at each measured point, which indicate the contribution of local noise sources to each microphone. The accuracy of the optical CT method is verified using a microphone array.