Numerical simulations of the isothermal turbulent jets mixing flows exhausted from two
different circular lobed nozzles are presented in the present paper. The numerical studies
have been conducted using a Favre-Reynolds Averaged Navier-Stokes approach, using the
second-order Reynolds Stress Model (RSM) and structured mesh. The
validation of the numerical results with experimental data has been carried out only with
one nozzle for the same configuration. This comparison shows reasonable agreement,
principally, in terms of centreline longitudinal velocity, longitudinal fluctuating
velocity and streamwise vorticity. In the second part, the effects of the inlet isothermal
lobed jet on the mixing process with variable density have been studied numerically. For
the same area exit geometries (axisymmetric and asymmetric), a qualitative comparison of
the numerical results with experimental data have been presented. All these indicated the
better mixing enhancement performance of a lobed nozzle over asymmetric and axisymmetric
nozzles respectively.