Wavelet analysis of wall-pressure fluctuations in a supersonic blunt-fin flow

Measurements of wall-pressure fluctuations in a Mach 3 flow over a blunt fin were analyzed with the continuous wavelet transform. This technique offers a fresh approach to the problem of inferring flow structure from the wall-pressure signal. The time scales associated with large-scale structures in the flow turbulence and with shock crossing events are identified as distinct local maxima in the distribution of energy over the wavelet scales. By using the extreme in the wavelet spectrum as a reference, the signal can be filtered in the space of wavelet scales to separate the contribution to the pressure fluctuations of flow turbulence and separation shock motion.