Measurement of the Acceleration Field of the High-Speed Jet Sound Producing Region

With the aim of being capable of controlling the sound created by high-speed jets or engine exhausts, a preliminary experiment, using a near-field azimuthal array of 15 pressure sensors and a far-field array of 6 microphones, pointed out the region of highest sound production in the turbulent flow where a dual-time particle image velocimetry (DT-PIV) investigation is now being carried out. This measurement technique enables access to time-derivatives of the velocity field which is a quantity of great interest for developing prediction capabilities crucial for closed-loop flow control. Jointly, a flow control device using synthetic jets is developed and PIV measurements are taken with and without the control to assess the effectiveness of such devices for aeroacoustic flow control.