In this work three-dimensional turbulent and separated jets are numerically studied and compared with experimental data. The basic idea of the separated jet burner consists in separating fuel and oxidizer injection to dilute reactants with combustion products before the reactants mix. The computation is achieved using the finite-volume numerical method. The turbulence is modeled using a second order Reynolds Stress Model (RSM) by Launder Reece Rodi. A non uniform grid is applied and particularly tightened close to the exit jets in order to capture the near field mechanisms. The validation of the numerical tools is done by comparison with experimental data of the non ventilated jets. Ventilated jets are investigated only numerically. The obtained results show that mixing is improved using three jets compared to the single jet. A comparison between computed ventilated and non ventilated jets is presented. It yields a larger velocity mean value, but a decreasing of the corresponding root mean square of the turbulent velocity fluctuations (rms). (C) 2016 Elsevier Ltd. All rights reserved.