Based on the kinetic theory, a three-dimensional multiple-relaxation-time discrete Boltzmann model (DBM) is proposed for nonequilibrium compressible reactive flows where both Prandtl number and specific heat ratio are freely adjustable. There 30 moments of distribution functions, an efficient thirty-velocity utilized. Through Chapman–Enskog analysis, Navier–Stokes equations can be recovered fro...

Wind tunnel is a test facility used to simulate the flight conditions. It allows us to make a reusable prototype and test it in the tunnel in low cost. Hypersonic wind tunnels operate at hypersonic speeds ie, with a mach number greater than 6. For doing experiments, it is necessary to maintain a constant pressure in the settling chamber of the tunnel so that we get the desired mach number and m...

Ignition and relighting in supersonic flows is an important challenge for the design of hypersonic propulsion systems. Supersonic compressible interest exhibit much larger local variations velocity, shear, thermodynamic state than their incompressible counterparts. Thus, it to study relationship between ignition kernel evolution, initial spark location, kernel’s subsequent flow history. We leve...

Numerical simulations of axisymmetric flows over reentry configurations at hypersonic conditions using a Navier-Stokes solver are presented. The Navier-Stokes equations are modified using Park’s two-temperature model to account for thermochemical nonequilibrium and weak ionization effects. The finite-volume method is used to solve the set of differential equations. The code has the capability t...

A modification of the Roe scheme aimed at low Mach number flows is discussed. It improves the dissipation of kinetic energy at the highest resolved wave numbers in a low Mach number test case of decaying isotropic turbulence. This is done by scaling the jumps in all discrete velocity components within the numerical flux function. An asymptotic analysis is used to show the correct pressure scali...

An accurate and compact part-spectrum k-distribution database has been developed for the two most important radiating species N and O encountered in hypersonic nonequilibrium flows. The database allows users to calculate the desired full-spectrum k-distributions through look-up and interpolation, providing an efficient means to perform radiative transfer calculations. A detailed methodology of ...

We describe here two innovative in-flight measurement techniques for onboard operation on atmospheric re-entry demonstrator vehicles like EXPERT or pre-X actually in study in Europe. The first one is the Electron Beam Fluorescence (EBF) technique which aims at characterising shock layer chemistry through measurements of density, rotational and vibrational temperatures of N2 and NO in low densit...

Most of deterministic solvers for rarefied gas dynamics use discrete velocity (or discrete ordinate) approximations of the distribution function on a Cartesian grid. This grid must be sufficiently large and fine to describe the distribution functions at every space position in the computational domain. For 3-dimensional hypersonic flows, like in re-entry problems, this induces much too dense ve...

The effects of expansion waves on incident shock-wave/boundary-layer interactions (SWBLIs) at a Mach number 4.96 are experimentally studied. flow characteristics the interaction zone under various intensities and positions shock wave quantitatively analyzed. weaken intensity encountered, thereby weakening SWBLIs. With an increasing distance between zone, total wall pressure jump interference le...