Effect of Free Jet on Refraction and Noise

摘要: FThis article investigates the role of a free jet on sound radiated from jet. In particular, an infinite wind tunnel, which simulates forward flight condition, is compared to that finite tunnel. The second configuration usually used in experiments, where microphones are located static ambient medium far outside To study effect noise, both propagation and source strength need be addressed. this work, exact Green’s function locally parallel flow derived for simulated case. Numerical examples presented show reduction magnitude aft arc increase condition. tunnel refraction sensitive location most pronounced arc. A Reynoldsaveraged Navier-Stokes solution (RANS) yields required mean turbulence scales mixing noise spectrum calculations. addition sound/flow interaction, separate elongation noisegenerating region studied. Comparisons made with experiments cases. Finally, standard free-jet shear corrections convert measurements ideal arrangement evaluated.