Underexpanded jets have become widely used in studies of rarefied-gas flows [1][3] and aerodynamics of hypersonic probes in wind tunnels [4]-[7]. The objective of the present study is to analyze shapes and flow parameters in internal regions of hypersonic underexpanded viscous jets, and to apply the jet theory to hypersonic studies. Analytical solutions [7] are used for estimating internal flow...

In this paper an upwind algorithm based on Roe’s scheme is presented for solution of PNS equations. Non iterative-implicit method using finite volume technique is used. The main advantage of this approach, in comparison with similar upwind methods, is reduction of oscillations around sonic line. This advantage causes the present method to be able to analyze supersonic flows with free stream Mac...

To aid in understanding the different topics discussed in the current Lecture Series and to provide background material for interested participants who may not have specialized training in this field, a brief summary of the fundamental attributes of hypersonic flows is given. Many of the topics that are introduced in this section will be elaborated further in contributions related to specific s...

This paper summarizes the current efforts at VKI and collaborating institutions in understanding nonequilibrium phenomena in hypersonic flows. Research activities related to “Detailed gas chemistry models,” “Kinetic theory,” and “Rarefied gas effects” are described. Keywords— Atmospheric entry flows, Thermo-chemical nonequilibrium flows, Computational Fluid Dynamics.

Hypersonic rarefied flows near a wedge, disk, plate, and sphere were studied under the conditions of wind-tunnel experiments [1-8] and hypersonic flights. The direct simulation MonteCarlo (DSMC) method [9] is used to study the influence of similarity parameters on aerodynamic coefficients in He, Ar, N2, and CO2. It is found that, for conditions approaching the hypersonic stabilization limit, th...

A parallel computational fluid dynamics code has been developed for the study of aerodynamic heating problem in hypersonic flows. The code employs the 3D Navier-Stokes equations as the basic governing equations to simulate the laminar hypersonic flow. The cell centered finite volume method based on structured grid is applied for spatial discretization. The AUSMPW+ scheme is used for the invisci...

Rarefied gas phenomena are found in a wide variety of hypersonic flow applications, and accurate characterization of such phenomena is often desired for engineering design and analysis. In atmospheric flows involving high Mach numbers and/or low densities, underlying assumptions in a continuum fluid dynamics description tend to break down, and distributions of both molecule velocity and interna...

2 Research interests of the laboratory include hypersonic flows and computational fluid dynamics, among other things 3 Leading staff of the laboratory:

The development of aeronautics and astronautics, from its practical beginning with the Wright brothers’ first airplane on 17 December 1903, has been driven by one primary aim to fly faster, higher and cheaper. There is an exponential increase in both aircraft speed and altitude over the past 100 years, and now the era of the hypersonic flight is approaching [1]. With practical hypersonic airpla...