Wall pressure spectra model including favorable and adverse pressure gradients

Abstract

A wall pressure spectra model was proposed for turbulent boundary layer flows in zero, favorable and adverse pressure gradients. The model was developed based on measurements on a flat plate model and a NACA 0012 airfoil installed above the plate, which produced mild and strong favorable and adverse pressure gradients on the plate flows, depending on the airfoil position. The proposed model is validated by selected measurement data from the literature, covering flows with the boundary layer shape factor in a range of 1.23 ≤ H ≤ 2.12 and the Reynolds number of 167 ≤ Re τ ≤ 3992. The model shows good prediction accuracy for all flow conditions of the selected database. It is to be highlighted that the pressure gradient effect on the low-frequency spectral slope is considered, which leads to good agreement of the predicted low-frequency spectral shape with the measured spectra. Compared with the selected published models, an improvement in the prediction accuracy is demonstrated.