Experimental Investigations of an Internal Flow Generated by Porous Injection

Abstract

An anisothermal channel flow generated by a porous injection is investigated in details for different Reynolds numbers of the injection in order to highlight the impact of the microstructure of porous material on the flow development. Two types of porous materials, being characterized by different matrices and pore sizes are studied: a coarse bronze porous plate (30% porosity and 100 μm average pore diameter) and a stainless steel porous plate (30% porosity and 30 μm average pore diameter). Particle image velocimetry, hot-wire anemometry, and cold wire thermometer measurements lead to the comparison of mean profiles, rms profiles, and energy spectra for the velocity and temperature fields. Two-point spatial correlations for the fluctuating velocity are also calculated. In the case of the coarse bronze plate, the flow is slightly fluctuating with big space coherence. In the opposite, the results obtained with the fine pore plate show a flow close to a fully developed turbulent channel flow. The comparison of the aerodynamic field with computational simulations based on a Reynolds-averaged Navier-Stokes (RANS) model underlines the difficulties to reproduce exactly the evolution of the mean and fluctuating velocities in all the explored part of the channel.