In this thesis we investigate the ability of the Runge-Kutta Discontinuous Galerkin (RKDG) method to provide accurate and efficient solutions of the Boltzmann equation. Solutions of the Boltzmann equation are desirable in connection to small scale science and technology because when characteristic flow length scales become of the order of, or smaller than, the molecular mean free path, the Navi...

A preliminary hybrid particle-continuum computational framework for simulating hypersonic interacting flows is proposed. The framework consists of the direct simulation Monte Carlo-Information Preservation (DSMC-IP) method coupled with a NavierStokes solver. Since the DSMC-IP method provides the macroscopic information in each time step, determination of the continuum fluxes across the interfac...

The transport characteristics of the unsteady flow field in rarefied plasma plumes is crucial for a pulsed vacuum arc which particle distribution varies from 1016 to 1022 m−3. direct simulation Monte Carlo (DSMC) method and particle-in-cell (PIC) are generally combined study this kind field. DSMC simulates motion neutral particles, while PIC charged ions. A hybrid DSMC/PIC algorithm investigate...

Abstract An in-house Direct Simulation Monte Carlo (DSMC) code has been developed using an object-oriented interface for the purpose of eventually modelling gas and plasma microflows in micromechanical systems, by coupling it with existing Particle-In-Cell (PIC) solver. The is validated canonical flow problems such as micro-Couette micro-Poiseuille flows. Since emphasis on supersonic highly com...

A parallel direct simulation Monte Carlo method is developed, which uses dynamic domain decomposition to solve the problem of load unbalancing among processors. In addition, variable time-step method and unstructured adaptive mesh are implemented, respectively, for reducing the computational time and increasing the accuracy of solution. Associated flow chart of the proposed DSMC method is illus...

The Direct Simulation Monte Carlo (DSMC) method, developed originally to calculate rarefied gas dynamical problems, is applied to continuous flow including shocks assuming that the Knudsen number is sufficiently small. In particular, we study the formation of spiral shocks in the accretion disc of a close binary system. The method involves viscosity and thermal conduction automatically, and can...

This paper presents a model for predicting the parallel scalability of Direct Simulation Monte Carlo (DSMC) simulations of rareeed gas ow. The performance implications of diierent connection topologies are considered. The analysis is independent of the simulation architecture, gridding technique, collision model, and implementation technique. The model is validated and constants of the model de...