A comparison between different wall pressure measurement devices for the separation and analysis of TBL and acoustic contributions

The wall pressure measured by an array of flush mounted microphones subject to a flow results from two components. The first one is due to the pressure fluctuations generated by vortices convected by the flow in the turbulent boundary layer developed on the wall, and the second one results from acoustic waves that are emitted by some acoustic sources. Different type of sensor arrays can be used to characterize the first or second components, or even both. In all cases, a major difficulty is to separate as well as possible their contributions to the measurements. Different techniques are reviewed in this chapter to achieve this goal, based on either the measurement device itself or the post processing method. All approaches are implemented in a unique experimental setup, conducted in the frame of the ADAPT Clean Sky 2 project, allowing to objectively highlight their advantages and drawbacks.