プラズマアクチュエータを用いたキャビティ音の制御

抄録

The aim of this investigation is to clarify the effectiveness of aerodynamic noise control with the dielectric barrier discharge (DBD) plasma actuator (PA) over the cavity. The sound and velocity fields of flow around cavity were measured with a low noise wind tunnel. The depth-to-length ratio of the cavity was D/L = 0.5 and 2.5. The flow around the cavity often makes acoustic radiation with resonance at specific freestream velocity. To control tonal noise, PAs were utilized. The PAs were mounted on the upstream surface of the cavity parallel to the freestream to induce streaks. The experiments were performed for 5 spanwise pitch of PAs, p/L = 0.5, 0.6, 0.75, 1.0, 1.25. As a result, the most intense reduction level of 33.4 dB was achieved for the smallest pitch of p/L = 0.5. The measurements of the velocity field turned out that three-dimensionality of the flow were induced by the actuation of the PAs.