The influence of the internal configuration of vessel reactors for the Supercritical Water Oxidation Process is evaluated by simulation and compared to experimental data. A one equation model is used to close the RANS equations and allows the reproduction of the experimental results. The model can be used for designing reactors working under hydrothermal flame looking at performance and flame stabilization. Geometrical parameters studied here are the distance between injector's outlet and reactor's ceiling and the injector inner diameter. The influence of operational parameters like Row velocity and inlet temperature is also verified. (C) 2014 Elsevier Ltd. All rights reserved,