TENSOR: Turbulent boundary layer and trailing Edge Noise Study Of flow past a porous surface at high Reynolds number

Two aspects of porous materials that substantially influence the turbulent boundary layer convecting over them are surface roughness and permeability, and although their individual effects is well documented, their combined action and non-linear interaction are poorly understood. Nevertheless, nature and engineering are replete with examples; therefore, a comprehensive study of turbulent flows over and past these surfaces is proposed at high Reynolds number. This is important because previous numerical studies were limited to low-moderate Reynolds number due to computational costs, while experiments have altered the surface roughness and permeability at the same time; thus, their relative contribution could not be assessed. Therefore, a novel methodology is proposed to decouple surface roughness from permeability, which will be used to examine their relative importance on noise and drag. The project pairs a researcher with experience in aeroacoustics with an expert in applied experimental fluid mechanics, achieving a mutually beneficial exchange of knowledge. The Fellow will parametrically survey the effects of porous materials on velocity-pressure statistics, followed by a detailed investigation of the underlying flow physics using Tomographic PIV velocimetry to establish cause-and-effect mechanisms between porous materials and turbulent boundary layer. Finally, to measure the relative contribution of surface roughness and permeability on the scattering efficiency of trailing-edge, the ratio of the scattered far-field to the incident wall-pressure statistics will be quantified at the anechoic wind tunnel. The project will target its dissemination activities at
scientific communities where the immediate impact is expected, including thermal engineering and biology. Together with the host's capabilities and track record, will ensure successful completion of this ambitious research project and maximally support the fellow's career development.