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