Edney type IV and type VII shock-shock interactions are complex hypersonic flow phenomena. They are characterized by a supersonic jet which reaches far into the flow field. An experimental investigation of the inner jet structure is difficult, especially in cases where the jet is subject to high-frequency unsteady movements. The present paper provides insight into the jet structure by means of ...

Computational Fluid Dynamic (CFD) surrogates are developed to efficiently compute the aerodynamic heating and unsteady pressure loads for a structurally and thermally compliant skin panel in hypersonic flow. In order to minimize the computational overhead, the surrogates are constructed using steady-state CFD flow analysis. Unsteady terms in the aerodynamic pressure are incorporated using pisto...

Three time-domain damping/frequency/flutter identification techniques are discussed; namely, the moving-block approach, the least-squares curve-fitting method, and a system-identification technique using an autoregressive moving-average model of the aeroelastic system. These methods are evaluated for use with time-intensive computational aeroelastic simulations, represented by the aeroelastic t...

Future hypersonic vehicles are likely to use sharp leading edges on wings and engine inlets to reduce drag. The radius of curvature associated with such structures may be one centimeter or less. The very small size leads to high heating rates that can be accommodated using advanced materials. An additional aspect of the small size concerns the basic gas dynamics. At such small scales, the conti...

The interaction of a diffusing outgas flow from a sphere nose opposing a hypersonic free stream is studied numerically by the direct simulation MonteCarlo technique under the transitional rarefied-gas-flow regime conditions at Knudsen numbers from 0.016 to 1.5 and blowing factors from 0.15 to 1.5. Strong influences of the blowing factor (the ratio of outgas mass flux to upstream mass flux) and ...

Significant advancements in hypersonic airbreathing vehicle technology have been made in the country’s research centers and industry over the past 40 years. Some of that technology is being validated with the X-43 flight tests. This paper presents an overview of hypersonic airbreathing technology status within the US, and a hypersonic technology development plan. This plan builds on the nation’...

The interaction of a diffusing outgas flow from a sphere nose opposing a hypersonic free stream is studied numerically using the direct simulation Monte-Carlo technique under the transitional rarefied-gas-flow regime conditions at Knudsen numbers from 0.016 to 1.5 and blowing factors from 0.15 to 1.5. Strong influences of the blowing factor (the ratio of outgas mass flux to upstream mass flux) ...

Koren, B. and P.W. Hemker, Damped, direction-dependent multigrid for hypersonic flow computations, Applied Numerical Mathematics 7 (1991) 309-328. A nonlinear multigrid technique with improved robustness is developed for the solution of the steady Euler equations. The system of nonlinear equations is discretized by an upwind finite volume method. Collective symmetric point Gauss-Seidel relaxati...

In recent years, direct numerical simulation (DNS) has become a powerful tool to study the stability and transition of compressible boundary layers. The difficulty in using explicit methods for DNS of hypersonic flow is the limitation of the temporal steps since the Navier-Stokes equations are stiff for explicit numerical schemes. Due to the progress in computer techniques in recent years, one ...