WSEAS Transactions on Fluid Mechanics
Print ISSN: 1790-5087, E-ISSN: 2224-347X
Volume 14, 2019
Numerical Simulation of the Spatial Turbulent Mixing Supersonic Forced Jets in CoFlow
Authors: , ,
Abstract: The most significant problem in many industrial applications such as flows in combustors and nozzles is the study of mixing properties of jets. At present, the problem of control of enhancing the mixing in the low-speed flows is well studied while in the high-speed flows this problem is still important. In this paper the supersonic turbulent forced jet of perfect gas in a supersonic coflow is studied numerically. The simulation is performed using the three-dimensional LES filtered Navier–Stokes equations coupled with the Smagorinsky turbulence model, the solution of which is based on the third-order non-oscillatory (ENO) scheme. For the turbulent jet control and the mixing enhancement problems the inlet deterministic excitation (forcing) with various frequencies and perturbation amplitudes is proposed. It is revealed that the behaviour of the growth of shear layer is governed with deterministic forcing at the entrance. A namely, including forcing gives much more quickly pairing of the vortices and the rise of thickness of shear layer in compare to the ‘natural’ jet (without forcing). Additionally, the variation of excitation frequency nonuniformly influences on the rolling up of the vortices; the decrease of frequencies slows down roll-up process and enlarges vortices stretch in the streamwise direction. The obtained turbulence properties are in good agreement with experimental data.
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Keywords: Numerical simulation, supersonic jet, perfect gas, Navier-Stokes equations, mixing enhancement, forced jet, spectral initial conditions
Pages: 70-78
WSEAS Transactions on Fluid Mechanics, ISSN / E-ISSN: 1790-5087 / 2224-347X, Volume 14, 2019, Art. #8