EFFECT OF INFLOW CONDITIONS ON UNDER-EXPANDED SUPERSONIC JETS

Authors : MM Ashraful Alam, Toshiaki Setoguchi

Pages : 17-30

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Publication Date : 2012-03-01

Article Type : Research Paper

Abstract :The present work involves numerical simulations to investigate the effect of inflow condition on aerodynamic and shock characteristics of under-expanded turbulent jets from sonic nozzle. The TVD finite volume method was carried out and two equation k-ε turbulence model was used to model the turbulent stresses of the compressible flows in the present simulations. The jet pressure ratio was settled from 1.893 to 6.0 for generating perfectly expanded to moderately high under-expanded jets. The pressure and Mach number distributions on jet axis, and the flowfield structure was visualized by density distributions. The potential core and supersonic flow lengths were also measured to make a quantitative investigation on the jet structure. The effect of inflow condition at nozzle inlet was found to be pronounced resulting in the sonic line moved upstream of the nozzle throat. Moreover, numerically predicted results were compared with the experimental data to validate the present numerical code.
Keywords : Compressible flow, numerical analysis, potential core, shock wave, supersonic flow lengths