An experimental study of flow characteristics within zero-pressure-gradient turbulent boundary layers at high Reynolds numbers has been performed. Various rough wall configurations were used to provide a diverse data set. Velocity and pressure measurements were performed using four-sensor hotwire probes and B&K 4138 1/8-inch microphones respectively. The aim of the paper was to examine the possible relationship between the scaling of the low-frequency portion of the wall pressure spectrum and the velocity spectrum and statistics throughout the boundary layer. Three previously studied low-frequency scalings were considered: the classical scaling (velocity scale U_r, distance scale S), convection velocity defect (U_e - U_c, 5), and mean boundary layer velocity defect (U_e - U, δ, also known as the Zagarola-Smits scaling). A default scaling (U_e,δ) was introduced as a control for comparison metrics. While the default scaling poorly collapsed the pressure and velocity data, it confirmed a scaling relationship between the two of the type expected from the Poisson equation. The convection velocity and Zagarola-Smits scalings collapsed the rough wall turbulence profiles and velocity spectra well, analogous to their strong performance in normalizing the low-frequency pressure spectrum.
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