A MODULAR PARTICLE-CONTINUUM NUMERICAL ALGORITHM FORHYPERSONIC NON-EQUILIBRIUM FLOWS byThomas Edward Schwartzentruber Chairperson: Iain D. Boyd Hypersonic vehicles traveling at high altitudes experience conditions ranging fromrarefied to continuum flow. Even within a mostly continuum flow, there may belocal regions of rarefied (or non-equilibrium) flow generated by sharp leading...

The non-isotropic image interrogation technique is applied to study the compressible supersonic and hypersonic flow regimes. Supersonic flow experiments are performed in a blow-down windtunnel where the wake turbulence downstream of a wedge-plate model configuration is studied in the transonic M=1.35 regime. The hypersonic experiments are conducted in a short duration facility at Mach 6 and the...

The transport of free ions through highly under-expanded jet flows of neutral gases and in the presence of applied electric fields is investigated by continuum-based numerical simulations. In particular, numerical results are described which are relevant to ion flows occurring in quadrupole interfaces of mass spectrometer systems. A five-moment mathematical model and parallel multi-block numeri...

The direct simulation Monte Carlo method (DSMC) has evolved over 50 years into a powerful numerical technique for the computation of thermochemcial nonequilibrium gas flows. In this context, nonequilibrium means that velocity and internal energy distribution functions are not in equilibrium forms due to a low number of intermolecular collisions within a fluid element. In hypersonic flow, nonequ...

This paper concerns the development and application of a gas-kinetic scheme based on the Bhatnagar–Gross–Krook (BGK) model for the Navier–Stokes equations in the study of hypersonic viscous flow. Firstly, we extend the gas-kinetic Navier–Stokes solver [K. Xu, A gas-kinetic BGK scheme for the Navier–Stokes equations and its connection with artificial dissipation and Godunov method, J. Comput. Ph...

PURPOSE To evaluate porcine vitreous flow and water flow rates in a new prototype hypersonic vitrectomy system compared to currently available pneumatic guillotine vitrectors (GVs) systems. METHODS Two vitrectors were tested, a prototype, ultrasound-powered, hypersonic vitrector (HV) and a GV. Porcine vitreous was obtained within 12 to 24 h of sacrifice and kept at 4°C. A vial of vitreous or ...

This paper applies the high-order finite-volume essentially nonoscillatory (ENO) schemes to unsteady hypersonic shock-shock interference heating on a circular cylinder. Compared with most of the current second-order numerical methods, which usually are not uniformly accurate, the EN0 schemes are able to achieve uniformly high-order accuracy with essentially no oscillation in simulating the aero...

An approximate analytical solution is obtained for hypersonic flow past a slender elliptic cone using second-order perturbation techniques in spherical coordinate systems. The analysis is based on perturbations of hypersonic flow past a circular cone aligned with the free stream, the perturbations stemming from the small cross-section eccentricity. By means of hypersonic approximations for the ...