**5.2 Jet effect**

**Figure 14** represent the distribution of pressure, temperature, density and streamlines of the fluid field with opposing jet configuration shows that the jet layer reattaches to the blunt body surface, and then a low temperature recirculation region is formed lead to the formation of a normal shock ward off from the blunt body nose. Where a recompression shock wave also formed downstream the reattachment region of the jet layer.

The interaction between the flow field and the solid structure determines the heating rate distributions. The temperature difference between the solid external surface and the fluid layer near the fluid-solid interface will change as the temperature field of the solid structure changes due to aerodynamic heating, which will affect in turn the heat transfer between the fluid and the solid domain. so, by introducing the opposing jet configuration the temperature was reduced from 1035 without jet to 854 with jet model, this led to a heat flux reduction estimated by 28.75%.
