Prediction and Measurement of Turbulent Boundary Layer Wall-Pressure Fluctuations on the Surface of a Single Panel at Low Mach Numbers

Wall-pressure fluctuations induced by a turbulent boundary layer, acquired in a wind tunnel environment, are analyzed for flow speeds between 0.05 and 0.12 Mach. Three microphone configurations are considered: flush mounted with a standard grid cap, flush mounted with a pinhole cap, and a recessed approach beneath a Kevlar sheet. A selection of existing single-point frequency spectrum models, for turbulent boundary layer wall-pressure fluctuations, are reviewed and compared to measurements from the Carleton University wind tunnel facility to determine the most appropriate model for subsonic flows. The measured and predicted frequency spectra are compared in dimensional and non-dimensional forms to investigate dependencies on Mach number and turbulent boundary layer thickness.