Wall-pressure fluctuations induced by a compressible jet in installed configuration

Wall-pressure fluctuations induced by a subsonic jet over a wing/flap scaled model have been experimentally investigated in a large-scale wind-tunnel facility. The pressure field on the wing was measured by flush-mounted pressure transducers installed on the pressure side, whereas synchronized near-and far-field pressures were measured using microphone arrays. Experiments were carried out with the coaxial jet operating in single-stream-like jet conditions (that is, with the primary and secondary jets at the same flow conditions) for two different jet Mach numbers of Mj 0.6 and Mj 0.75. Flight effects were explored as well for the jet flow condition of Mj 0.75 and the flight-stream Mach number Mf set equal to 0.18. Data were analyzed in the time and frequency domains in order to characterize the wall-pressure statistics as well as the cross statistics between the wall-pressure fluctuations and the near-/far-field pressure. Particular attention was devoted to determining universal scalings of the spectral quantities using both static and flight parameters. Semiempirical models commonly used in canonical turbulent boundary layers to reproduce the wall-pressure coherence were tested and verified for both the static and flight conditions.