This paper introduces a lot of situations about the Computational Fluid Dynamics (CFD) analysis of backward facing step flows. The main point of this paper is incompressible flow in a backward step, measured by drivers and Seegmiller experiments. The researchers concluded that validation parameters chosen for the study are the locations of the surface hydrostatic pressure and the reattachment compression impact downstream of the step. The surface static pressures predicted by WIND using a two-equation SST turbulence model are shown below. This figure includes a comparison of earlier versions of NPARC and WIND with experimental data. The WIND code slightly overestimates the surface pressure drop from the free flow value to about 5% of the corner value of the separation area (base pressure). This may be due to the fact that the transition point is experimentally unknown and not accurately predicted by the natural transition of the turbulence model. However, this over-forecasting predicts the previous pressure drop closer to the experimental results than the AEDC PARC, TUFF, and GASP codes using the Baldwin Lomax, KE, and Cebeci, and Smith models, respectively. The rest of the forecast for WIND pressure is in good agreement with the forecast pressure.