The receptivity of a hypersonic boundary layer to three-dimensional wall perturbations is investigated in this paper by numerical simulations. The work is motivated by Tumin’s [1] theoretical analysis on the receptivity of compressible boundary layers to three-dimensional wall perturbations with the help of the biorthogonal eigenfunction system. Specifically, receptivity processes of a Mach 5.9...

The effects of rarefaction and nonequilibrium processes on hypersonic rarefied-gas flows over blunt bodies have been studied by the Direct Simulation Monte-Carlo technique (DSMC) and by solving the full Navier-Stokes equations and the equations of a thin viscous shock layer (TVSL) under the conditions of wind-tunnel experiments and hypersonic-vehicle flights at altitudes from 60 to 110 km. The ...

Hypersonic vehicles with single-stage-to-orbit (SSTO) capability present a major design challenge. Such vehicles reflect highly integrated airframe and propulsion systems and are also known to exhibit a large degree of interaction between the airframe and engine dynamics. Consequently, even simplified hypersonic models are characterized by tightly coupled nonlinear equations of motion. The vehi...

We proposed rigorous definitions of Radon measure solutions for boundary value problems steady compressible Euler equations which modeling hypersonic-limit inviscid flows passing two-dimensional ramps, and their interactions with still gas pressureless jets. proved the Newton-Busemann pressure law drags body in hypersonic flow, constructed various physically interesting density containing Dirac...

a = speed of sound e = integrated amplification ratio for a linear instability, usually from location of first instability to transition k = roughness height Mw = Mach number at the nozzle wall, at the boundarylayer edge M1 = Mach number in the freestream N factor = ln A=A0, the linear-theory amplification ratio from onset of instability A0 usually to measured transition A Pmean = mean pitot pr...

This letter presents a new solution for the Tunguska event of June 30th, 1908. The solution has been obtained starting from seismic data, is in fair agreement with the observational evidence, and supports the asteroidal hypothesis for the origin of the Tunguska cosmic body. It is based on an improved model of the hypersonic flow around a small asteroid in the Earth’s atmosphere.

Many astrophysical flows occur in inhomogeneous media. We briefly discuss some general properties of the adiabatic and radiative inhomogeneous systems and discuss the relevance of those properties to the planetary nebulae systems. We then focus on radiative hypersonic bullets and the applicability of this model to planetary and protoplanetary systems such as CRL 618, NGC 6543, Hen 3-1475.

Hypersonic vehicles are an important development direction in aerospace, and their will have a significant impact on world security, the of cosmic space resources related disciplines. Along with rapid modern aircraft, landing gear is commonly used retractable technology, which brings series problems, such as design hatch retraction heat sealing mechanism evaluation air tightness. This paper tak...