主流乱れがキャビティ音および音源に及ぼす影響

抄録

Flow and acoustic fields for cavity flows were directly simulated for various intensities of freestream turbulence to clarify what effects freestream turbulence had on cavity tones. The depth-to-length ratio of the cavity, D/L, was 0.5 and 2.5. The incoming boundary layer was laminar. Acoustic resonance in the direction of the cavity depth occurred in the flow over the cavity with D/L = 2.5. The results for the intensity of freestream turbulence 2.3% revealed that the reduced level of cavity tone in a cavity flow with acoustic resonance was greater than that in a flow without acoustic resonance. The contributions of the intensity and spanwise coherence of the sound source to reducing the cavity tone were investigated. The effects of spanwise coherence of the sound source ware dominant in the cavity flow with acoustic resonance. However, these factors were almost the same as those without acoustic resonance.