Investigation of the generation of nonlinear waves by a temporal supersonic round jet
Résumé
A temporally-developing supersonic round jet at a Mach number of 2 and at a diameter-based Reynolds number of 3125 is computed by Direct Numerical Simulation in order to investigate sound generation mechanisms in supersonic axisymmetric sheared flows. It is found that as the potential core closes, strong, steep pressure waves are radiated. At the same time, high turbulence levels and supersonic convection velocities are found inside the jet. Positive levels of skewness of the pressure fluctuations and of its time derivative are observed in the radiated sound field. This is similar to measurements made in the pressure fields of supersonic jets exhibiting crackle noise.
Domaines
Mécanique [physics]
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