The effects of cross section variations on the pressure distribution around a long axisymmetric body

In the present study, the impacts of embedding belts are experimentally studied for a supersonic flow field around a long axisymmetric body. Also, the longitudinal and circumferential pressure coefficients along with the boundary layer profile are investigated for −2 to 6 degrees angles of attack. To this end, two conical-cylindrical belts were installed at the middle and end parts of ogival cylinder model. To ensure the turbulent flow around the model, a trip strip causing artificial disturbances is utilized and the acquired results are compared with the acquired results from the model without a trip strip. To study the effects of the cross section variations on the pressure distribution as well as the boundary layer profiles, three different belts with various leading edge angles were installed at different locations along the cylindrical section of the model. These belts significantly affected both the surface pressure distribution and the boundary layer profile. Passing of flow over the belt leads to sudden variations in pressure coefficient distribution on the belt that is due to sudden cross section variations and consequent development of reverse flow or flow separation regions and production of vortices along the flow path. Also, the presence of belt leads to the development of oblique shock wave on the model, which in turn reduces the Mach number downstream the belt. Studying the circumferential pressure distribution reveals that the presence of belt leads to more asymmetric flow downstream the model, which is intensified as the angle of attack increases.