For simulating rarefied gas flows around a moving body, an immersed boundary method is presented here in conjunction with the Direct Simulation Monte Carlo (DSMC) method in order to allow the movement of a three dimensional immersed body on top of a fixed background grid. The simulated DSMC particles are reflected exactly at the landing points on the surface of the moving immersed body, while t...

There are many flows fields that span a wide range of length scales where regions of both rarefied and continuum flow exist and neither direct simulation Monte Carlo (DSMC) nor computational fluid dynamics (CFD) provide the appropriate solution everywhere. Recently, a new viscous collision limited (VCL) DSMC technique was proposed to incorporate effects of physical diffusion into collision limi...

The direct simulation Monte Carlo (DSMC) method is a stochastic approach to solve the Boltzmann equation and is built on various numerical schemes for transport, collision and sampling. This work aims to compare and contrast two popular O(N) DSMC collision schemes no-time-counter (NTC) and majorant collision frequency (MCF) with the goal of identifying the fundamental differences. MCF and NTC s...

The direct simulation Monte Carlo (DSMC) method is versatile computational technique suitable for the simulation of a wide range of gas ows. It can deal with thermo-chemical non-equilibrium eeects with relative ease. However its computational cost has limited its application to rareeed or simple transitional ows. However DSMC is well suited to implementation on powerful multi-processor architec...

A modular particle-continuum (MPC) numerical method is used to simulate steady-state hypersonic flows which exhibit local regions of non-equilibrium embedded within mainly continuum flow fields. The MPC method loosely couples direct simulation Monte Carlo (DSMC) and Navier-Stokes (NS) methods which operate in different regions, use different mesh densities, and are updated using different sized...

A new discrete velocity scheme for solving the Boltzmann equation is described. Directly solving the Boltzmann equation is computationally expensive because, in addition to working in physical space, the nonlinear collision integral must also be evaluated in a velocity space. Collisions between each point in velocity space with all other points in velocity space must be considered in order to c...

The main objective of this study is to explain the experimental observations. To simulate material ablation, plume formation and its evolution, we developed a combined molecular dynamics (MD) and direct simulation Monte Carlo (DSMC) computational study of laser ablation plume evolution. The first process of the material ablation is described by the MD method. The expansion of the ejected plume ...

Cyber-physical systems (CPS) require model checking to guarantee the functional correctness of software models, providing counterexamples in case of violations. Domain-specific model checking (DSMC) allows to apply model checking to specific application domains. DSMC hides the complexity of using a model checker by translating from a domain-specific modeling language (DSML) to the model checker...

Freeze-drying is a low-pressure, low-temperature condensation pumping process widely used in the manufacture of pharmaceuticals for removal of solvents by sublimation. Key performance characteristics of a freezedryer condenser are largely dependent on the vapor and ice dynamics in the low-pressure environment. The main objective of this work is to develop a modeling and computational framework ...

The use of assistive devices to control the loss strength and range motion hemiplegic patients is becoming common. It difficult develop a precise approach for knee orthosis system because unpredictability dynamics unwanted subject’s spasm, jerk, vibration during gait assistance. In this study, an adaptive neuro-fuzzy inference (ANFIS) based on nonlinear disturbance observer (NDO) dynamic slidin...