收敛扩散喷管超音速喷射噪声和前向飞行效应
Flow and far-field noise measurements are taken on a conical Convergent-Divergent nozzle similar to the nozzles employed on high-performancetactical jets. Matching flow and far-field computations are presented,produced by Large Eddy Simulation and the Kirchhoff integral method.The conditions examined are those in which the nozzle is operated at itsdesign Mach number of 1.56 while forward flight is simulated at Machnumbers of 0.1, 0.3 and 0.8. Both measurement and LES show thatincreasing forward flight Mach number to the high subsonic rangeshortens the initial shock cell size, and weakens the shock cells induced bythe nozzle throat relative to the shock cells induced by the nozzle lip. LESshows that high forward flight speed substantially reduces the noiseradiated into the forward quadrant where shock noise is dominant. It alsoremoves the screech tone entirely.