Acoustic Characteristics of Laminar–Turbulent Transition in a Flat Plate Based on PSE and FW–H

In this study, nonlinear parabolized stability equation (PSE) and wall-resolved large-eddy simulation (WRLES) are employed to simulate laminar–turbulent transition in a flat plate using the solver OpenFOAM. Fluctuations of boundary layer displacement thickness, pressure and velocity in laminar, transition and turbulence regions are compared in detail. By combining nonlinear PSE and porous-surface Ffowcs-Williams and Hawkings (FW–H) method, the acoustic characteristics in different regions of the flat plate are analyzed. Our results have shown that the fluctuations of boundary layer displacement thickness and pressure in the transition region begin to increase. Besides, the fundamental wave and subharmonic wave introduced at the inlet boundary have a significant influence on the spectral curves of flow field quantities and radiated noise.