Computational study of hypersonic rarefied gas flow over re-entry vehicles using the second-order Boltzmann-Curtiss constitutive model

• Main Authors: Chourushi, Tushar, Singh, Satyvir, Sreekala, Vishnu Asokakumar, Myong, Rho Shin
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Mechanical engineering::Fluid mechanics; Hypersonic Re-Entry Vehicles; Rarefied Gas Flows
• Online Access: https://hdl.handle.net/10356/156103
• Institution: Nanyang Technological University

The aerothermodynamics of re-entry vehicles vary significantly upon re-entry, descent, and landing, because of the drastic changes in atmospheric density and velocity. In highly rarefied regimes, the conventional Navier-Stokes-Fourier equations may not provide an accurate prediction of aerothermodynamic loads acting on these vehicles. To tackle these challenges, an explicit mixed-type modal discontinuous Galerkin method was developed, based on the second-order Boltzmann-Curtiss constitutive model and the Maxwell slip and Smoluchowski jump conditions. A comprehensive analysis was conducted for different configurations of re-entry vehicles under various degrees of rarefaction. The computational results show that the rotational mode of energy transfer for diatomic gases substantially affects the lift-to-drag ratio and stability of re-entry vehicles. The total drag and heat transfer rate of the second-order constitutive model remained smaller than those of the first-order constitutive model in the rarefied regime, which makes the second-order results in better agreement with the direct simulation Monte Carlo.