Blunt-body configurations are the most common geometries adopted for non-lifting re-entry vehicles. Hypersonic re-entry vehicles experience different flow regimes during flight due to drastic changes in atmospheric density. The conventional Navier-Stokes-Fourier equations with no-slip and no-jump boundary conditions may not provide accurate information regarding the aerothermodynamic properties of blunt-bodies in flow regimes away from the continuum. In addition, direct simulation Monte Carlo method requires significant computational resources to analyze the near-continuum flow regime. To overcome these shortcomings, the Navier-Stokes-Fourier equations with slip and jump conditions were numerically solved. A mixed-type modal discontinuous Galerkin method was employed to achieve the appropriate numerical accuracy. The computational simulations were conducted for different blunt-body configurations with varying freestream Mach and Knudsen numbers. The results show that the drag coefficient decreases with an increased Mach number, while the heat flux coefficient increases. On the other hand, both the drag and heat flux coefficients increase with a larger Knudsen number. Moreover, for an Apollo-like blunt-body configuration, as the flow enters into non-continuum regimes, there are considerable losses in the lift-to-drag ratio and stability.

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With the advancement of fabrication technology and miniaturization, fluid flows at micro-and nanoscales has received considerable attention. Flow characteristics in these systems significantly vary from those of macro-scale devices, due to geometric restrictions. In such cases, Navier-Stokes-Fourier(NSF) equations with no-slip condition may not be valid for studying gas flows inside a micro-cavity. This article therefore investigates the cavity flows using modified NSF equations with velocity slip and temperature jump conditions. In the present case, a monatomic gas is considered for modelling gas flows. To accurately predict the flow physics, mixed modal discontinuous Galerkin(DG) method is being developed. The flow characteristics of monatomic gas is studied by varying the Reynolds number(Re) and Knudsen number(Kn), respectively. Results obtained are compared with the previous results and are found to be in good agreement with them.