Surface temperature measurement of acoustic liners in the presence of grazing flow and thermal gradient

The development of turbofans with larger fan diameters, shorter inlets, and thinner walls forces the acoustic liners to be placed closer hot parts engines. This experimental study investigates combined effects large thermal gradients, grazing flow level on impedance liners. Previous studies have shown that a coupling between these three can exist. objective is thus understand underlying coupled phenomena, in order extract driving parameters for more accurate modeling. In ONERA B2A liner facility, temperature accurately regulated several types excitation provided. For purposes this study, test section heating device used obtain gradient backplate perforated plate sample. Infrared (IR) thermography measure distribution plate. measurement conducted configurations, determine which conditions dissipation exists. particular, possible control surface by high sound pressure highlighted.