Direct numerical simulation (DNS) has become a powerful tool in studying fundamental phenomena of laminar-turbulent transition of high-speed boundary layers. Previous DNS studies of supersonic and hypersonic boundary layer transition have been limited to perfect-gas flow over flat-plate boundary layers without shock waves. For hypersonic boundary layers over realistic blunt bodies, DNS studies ...

A preliminary hybrid particle-continuum computational framework for simulating hypersonic interacting flows is proposed. The framework consists of the direct simulation Monte Carlo-Information Preservation (DSMC-IP) method coupled with a NavierStokes solver. Since the DSMC-IP method provides the macroscopic information in each time step, determination of the continuum fluxes across the interfac...

This study uses the non-intrusive generalized polynomial chaos method to investigate the effects of uncertainties in the gas-surface interaction model on the hypersonic boundary layer flow over a flat plate. In particular, the polynomial chaos method is applied to assess uncertainties in the surface shear, normal stress, heat flux, flowfield temperature and density resulting from uncertain surf...

This work presents development of an oxygen-based diode laser absorption sensor designed to be used in a supersonic combustion ramjet engine inlet. The sensor uses free-space propagation of light from a vertical-cavity surface-emitting laser (VCSEL) to determine the temperature, velocity and angle of attack of an engine inlet in hypersonic flow. The report outlines the method of calculating the...

Since the beginning of the Mars planet exploration, the characterization of carbon dioxide hypersonic flows to simulate a spaceship's Mars atmosphere entry conditions has been an important issue. We have developed a Tunable Diode Laser Absorption Spectrometer with a new room-temperature operating antimony-based distributed feedback laser (DFB) diode laser to characterize the velocity, the tempe...

An analytical formulatton of the problem of hypersonic viscous interaction on a very slender body of revolution with a thick boundary layer and mass transfer is attempted. Particular attention is directed to the establishment of the mathematical restrictions necessary to ensure the existence of similar solutions of the laminar boundary layer equations for this class of problems. Yasuhara's anal...

Hypersonic flights, re-entry vehicles, and propulsion applications all require new materials that can perform in oxidizing or corrosive atmospheres at temperatures in excess of 2000°C and sometimes over the course of a long working life. Ultra High Temperature Ceramics (UHTCs) are good candidates to fulfill these requirements. Within this family, the ZrB2 and HfB2 based composites are the most ...

Application of the newly emerged space-time conservation element solution element (CESE) method to compressible Navier-Stokes equations is studied. In contrast to Euler equations solvers, several issues such as boundary conditions, numerical dissipation, and grid stiffness warrant systematic investigations and validations. Non-reflecting boundary conditions applied at the truncated boundary are...