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...

A hybrid modeling capability has been developed by coupling a CFD code to a DSMC code using a one-way coupled interface surface. Using a unique toolkit, named AEGIS, these surfaces can be generated for complex, arbitrary 3D shapes. The status of this technology development is described. Modifications that include non-equilibrium internal energy modeling in the CFD code and solid particulates fo...

Three-dimensional direct simulation Monte Carlo ͑DSMC͒ method is applied here to model the electron-beam physical vapor deposition of copper thin films. Various molecular models for copper-copper interactions have been considered and a suitable molecular model has been determined based on comparisons of dimensional mass fluxes obtained from simulations and previous experiments. The variable hard ...

Gas mixing in a T-shape micro mixer has been simulated using the Direct Simulation Monte Carlo (DSMC) method. It is considered that the adequate mixing occurs when the mass composition of the species, CO or N2, deviates below 1 % from their equilibrium composition. The mixing coefficient is defined as the ratio of the mixing length to the main channel’s height. As the inlet Kn increases, while ...

It is well known that for increasingly rarefied flowfields, the predictions from continuum formulation, such as the Navier–Stokes equations lose accuracy. For the high speed diatomic molecular flow in the transitional regime, the inaccuracies are partially attributed to the single temperature approximations in the Navier–Stokes equations. Here, we propose a continuum multiple temperature model ...

We report the successful simulation of detonation waves using the direct simulation Monte Carlo (DSMC) method. The simulations provide the full details of the coupled gas-dynamic and reaction effects as well as temperature, velocity, density, pressure, and species profiles for the detonation waves. The systems treated are simplified and clarified by restriction to the reaction A + M ---> B + M ...

An overview of recent work on Monte Carlo simulations of a granular binary mixture is presented. The results are obtained numerically solving the Enskog equation for inelastic hard-spheres by means of an extension of the wellknown direct Monte Carlo simulation (DSMC) method. The homogeneous cooling state and the stationary state reached using the Gaussian thermostat are considered. The temperat...

A particle approach using the Direct Simulation Monte Carlo (DSMC) method is used to solve the problem of blast impact with structures. A novel approach to model the solid boundary condition for particle methods is presented. The solver is validated against an analytical solution of the Riemann shocktube problem and against experiments on interaction of a planar shock with a square cavity. Blas...

We present an adaptive mesh and algorithmic refinement (AMAR) scheme for modeling multi-scale hydrodynamics. The AMAR approach extends standard conservative adaptive mesh refinement (AMR) algorithms by providing a robust flux-based method for coupling an atomistic fluid representation to a continuum model. The atomistic model is applied locally in regions where the continuum description is inva...