Direct Simulation Monte Carlo of Counter Flow Jet Interaction with Reentry Capsule Rarefied Flow

2019 ◽  
Author(s):  
Mostafa Raeisi ◽  
Meysam Mohammadi-Amin ◽  
Ramin Zakeri
Keyword(s):  
Monte Carlo ◽  
Direct Simulation Monte Carlo ◽  
Direct Simulation ◽  
Counter Flow ◽  
Rarefied Flow ◽  
Jet Interaction ◽  
Simulation Monte Carlo

Modelling of chemical reactions in hypersonic rarefied flow with the direct simulation Monte Carlo method

1996 ◽  
Vol 312 ◽  
pp. 149-172 ◽  
Author(s):  
Michael A. Gallis ◽  
John K. Harvey
Keyword(s):  
Monte Carlo ◽  
Chemical Reactions ◽  
Energy Exchange ◽  
Chemical Reactivity ◽  
Direct Simulation Monte Carlo ◽  
Direct Simulation ◽  
Rarefied Flow ◽  
Rarefied Flows ◽  
Exchange Processes ◽  
Simulation Monte Carlo

In this paper the phenomenon of chemical reactivity in hypersonic rarefied flows is examined. A new model is developed to describe the reactions and post-collision energy exchange processes that take place under conditions of molecular non-equilibrium. The new scheme, which is applied within the framework of the direct simulation Monte Carlo (DSMC) method, draws its inspiration from the principles of maximum entropy which were developed by Levine & Bernstein. Sample hypersonic flow fields, typical of spacecraft re-entry conditions in which reactions play an important role, are presented and compared with results from experiments and other DSMC calculations. The latter use traditional methods for the modelling of chemical reactions and energy exchange. The differences are discussed and evaluated.

Development of Object-Oriented Direct Simulation Monte Carlo Code for Modeling of Rarefied Flow around Geometries of Arbitrary Shapes

2011 ◽  
Vol 110-116 ◽  
pp. 2491-2496
Author(s):  
Sourabh Jain ◽  
Prabhu Ramachandran
Keyword(s):  
Monte Carlo ◽  
Heat Conduction Problem ◽  
Direct Simulation Monte Carlo ◽  
Object Oriented ◽  
Navier Stokes ◽  
Monte Carlo Code ◽  
Direct Simulation ◽  
Rarefied Flow ◽  
Simulation Monte Carlo ◽  
Arbitrary Shapes

Rarefied flows cannot be accurately simulated using Navier-Stokes (N-S) equations. The Direct Simulation Monte-Carlo (DSMC) technique is a particle based method for accurate simulation of flows under such conditions. A DSMC code is developed using an object-oriented (OO) approach which can simulate flows around arbitrary shapes. Hence, the flux from such boundaries can be correctly predicted. The object-oriented approach enables for easy modification of the code. For example, it is easy to use different collision models to implement different relaxation algorithm. The code is validated for the one-dimensional Fourier heat conduction problem. Results for the development of a shock due to supersonic flow over a 15 degree wedge are also presented. Inclined boundary of the wedge is correctly captured as the particles interact with the the exact shape of the boundary. Shock angle is found more than expected due to rarefaction effects.

Investigation of rarefied flow over backward-facing step in different rarefaction regimes using direct simulation Monte Carlo

2021 ◽  
pp. 1-28
Author(s):  
D. Nabapure ◽  
A. Singh ◽  
R.C.M. Kalluri
Keyword(s):  
Monte Carlo ◽  
Knudsen Number ◽  
Pressure Coefficient ◽  
Direct Simulation Monte Carlo ◽  
Flow Regimes ◽  
Direct Simulation ◽  
Backward Facing Step ◽  
Rarefied Flow ◽  
Simulation Monte Carlo ◽  
Velocity Pressure

Abstract Hypersonic aerothermodynamics for a re-entry vehicle approaching the earth’s atmosphere is critical in the exploration of space. These vehicles often encounter various flow regimes due to the density variations and have surface abnormalities. The backward-facing step (BFS) is one such simplified configuration for modeling anomalies around such space vehicles. The present work examines rarefied hypersonic flow over a BFS using the direct simulation Monte Carlo (DSMC) method. The purpose of this research is focused on exploring the various loads encountered by a re-entry vehicle passing through different altitudes covering different rarefaction regimes. The fluid considered was non-reacting air, with the free-stream Mach number as 25, and the Knudsen number considered ranged from 0.05-21.10. The influence of the Knudsen number on flow characteristics has been elucidated graphically in various streamwise directions. The normalised flow properties such as velocity, pressure, temperature and density showed an increasing trend with the Knudsen number due to compressibility and viscous heating effects. In all flow regimes, there was an appearance of flow recirculation. With rarefaction, the recirculation lengths decreased, whereas the boundary layer thickness showed an increase. The aerodynamic surface properties such as pressure coefficient, skin friction, and heat transfer coefficient, by and large, showed an increase with the Knudsen number. When the chemical reactions were accounted for and compared against the non-reacting flows, the velocity, pressure, and density field showed no marked variation; however, considerable variations were observed in the temperature field. Furthermore, the present study also depicts the compressibility factor contour, showing the flow regions that diverge from the ideal gas behaviour.

Numerical Methods for the Kinetic Theory of Fluids

2018 ◽  
Author(s):  
Sauro Succi
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Numerical Methods ◽  
Kinetic Theory ◽  
Computational Efficiency ◽  
Lattice Boltzmann ◽  
Direct Simulation Monte Carlo ◽  
Particle Methods ◽  
Direct Simulation ◽  
Simulation Monte Carlo

This chapter provides a bird’s eye view of the main numerical particle methods used in the kinetic theory of fluids, the main purpose being of locating Lattice Boltzmann in the broader context of computational kinetic theory. The leading numerical methods for dense and rarified fluids are Molecular Dynamics (MD) and Direct Simulation Monte Carlo (DSMC), respectively. These methods date of the mid 50s and 60s, respectively, and, ever since, they have undergone a series of impressive developments and refinements which have turned them in major tools of investigation, discovery and design. However, they are both very demanding on computational grounds, which motivates a ceaseless demand for new and improved variants aimed at enhancing their computational efficiency without losing physical fidelity and vice versa, enhance their physical fidelity without compromising computational viability.

Study on the Deposition Profile Characteristics in the Micron-Scale Trench Using Direct Simulation Monte Carlo Method

1998 ◽  
Vol 120 (2) ◽  
pp. 296-302 ◽  
Author(s):  
Masato Ikegawa ◽  
Jun’ichi Kobayashi ◽  
Morihisa Maruko
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Boundary Conditions ◽  
Gas Flow ◽  
Direct Simulation Monte Carlo ◽  
Low Pressure ◽  
Sputter Deposition ◽  
Direct Simulation ◽  
Simulation Monte Carlo ◽  
Profile Characteristics

As integrated circuits are advancing toward smaller device features, step-coverage in submicron trenches and holes in thin film deposition are becoming of concern. Deposition consists of gas flow in the vapor phase and film growth in the solid phase. A deposition profile simulator using the direct simulation Monte Carlo method has been developed to investigate deposition profile characteristics on small trenches which have nearly the same dimension as the mean free path of molecules. This simulator can be applied to several deposition processes such as sputter deposition, and atmospheric- or low-pressure chemical vapor deposition. In the case of low-pressure processes such as sputter deposition, upstream boundary conditions of the trenches can be calculated by means of rarefied gas flow analysis in the reactor. The effects of upstream boundary conditions, molecular collisions, sticking coefficients, and surface migration on deposition profiles in the trenches were clarified.

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