Effect of Knudsen Number on Blunt Body During Hypersonic Speeds for Reducing Drag

This paper employs the Navier-Stokes equations, which are modified to include a rotational non- equilibrium relaxation model to analyse the heat transfer, drag, and shock stand of distance for hypersonic flow past an axisymmetric blunt body for various levels of rarefaction including the rotational non-equilibrium effect. The commercial flow solver FLUENT is used to calculate the numerical solutions for laminar viscous hypersonic flow past a blunt body at Knudsen number (Kn) in continuum-transition regime with and without rotational nonequilibrium. The effects of rarefaction in the continuum-transition regime are modelled by applying the Maxwell velocity slip and temperature jump boundary conditions on the surface. The effects of the rotational nonequilibrium terms are discussed in this paper for both the continuum Kn≅0.1 and no slip flow regime Kn≤0.1 Study is performed for (M∞ = 6.5, 7, 7.1 and 8). Finally we conclude by comparing drag and heat transfer changes by changing Kn number. Effect of increase in Mach number is also studied and concluded.