Simulation of a Rectangular Cylinder in Cross Flow in a Microchannel Using Information Preservation (IP) Method

2007 ◽  
Author(s):  
U. Kursun ◽  
J. S. Kapat
Keyword(s):  
Gas Flow ◽  
Cross Flow ◽  
Direct Simulation Monte Carlo ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Information Preservation ◽  
Rectangular Cylinder ◽  
Characteristic Theory ◽  
Simulation Monte Carlo ◽  
Pressure Boundary Conditions

A numerical simulation is performed to study the characteristics of the gas flow over a constant temperature rectangular cylinder in a cross flow in a micro channel. The non-isothermal Information Preservation (IP) method is employed to eliminate the statistical scatter of Direct Simulation Monte Carlo (DSMC) at low Reynolds numbers. Pressure boundary conditions based on the characteristic theory are implemented in the algorithm. The simulation results are compared with the references available in the literature. This study will form a base for our future particle-atomistic hybrid computations.

Numerical Simulation of an Array of Rectangular Cylinders in Cross Flow in a Microchannel Using DSMC-IP

2008 ◽  
Author(s):  
U. Kursun ◽  
J. Kapat
Keyword(s):  
Numerical Simulation ◽  
Cross Flow ◽  
Direct Simulation Monte Carlo ◽  
Information Preservation ◽  
Domain Boundaries ◽  
Micro Flows ◽  
Characteristic Theory ◽  
Simulation Monte Carlo ◽  
Rectangular Cylinders ◽  
Pressure Boundary Conditions

A numerical simulation is performed to study the characteristics of the gas cross flow over an array of rectangular cylinders in a two dimensional microchannel. Since Direct Simulation Monte Carlo (DSMC) suffers from the statistical noise for low Re flows which are often encountered in micro-flows, the non-isothermal Information Preservation (IP) method is employed. Pressure boundary conditions based on the characteristic theory are implemented at the inlet and outlet domain boundaries. The simulation results are presented. This study will form a base for our future particle-atomistic hybrid computations.

The DSMC-IP Simulation of Microchannel Cross Flow Over a Staggered Array of Square Cylinders

2008 ◽  
Author(s):  
U. Kursun ◽  
J. Kapat
Keyword(s):  
Cross Flow ◽  
Direct Simulation Monte Carlo ◽  
Low Flow ◽  
Information Preservation ◽  
Square Cylinders ◽  
Flow Speeds ◽  
Characteristic Theory ◽  
Simulation Monte Carlo ◽  
Pressure Boundary Conditions ◽  
Statistical Noise

A numerical simulation is performed to study two-dimensional cross flow over a staggered array of square cylinders in a microchannel using the non-isothermal Information Preservation (IP) method. The IP method works concurrently with the Direct Simulation Monte Carlo (DSMC) eliminating statistical noise from the DSMC results at low flow speeds. Pressure boundary conditions at the inlet and outlet based on the characteristic theory implemented. This study will form a base for our future particle-atomistic hybrid computations.

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.

Mixing Enhancement of Two Gases in a Microchannel Using DSMC

2013 ◽  
Vol 307 ◽  
pp. 166-169 ◽  
Author(s):  
Masoud Darbandi ◽  
Elyas Lakzian
Keyword(s):  
Gas Flow ◽  
Flow Analysis ◽  
Direct Simulation Monte Carlo ◽  
Equilibrium Composition ◽  
Mass Composition ◽  
Mixing Enhancement ◽  
Mixing Process ◽  
Result Section ◽  
Flow Through ◽  
Simulation Monte Carlo

Microgas flow analysis may not be performed accurately using the classical CFD methods because of encountering high Knudsen number regimes. Alternatively, the gas flow through micro-geometries can be investigated reliably using the direct simulation Monte Carlo (DSMC) method. Our concern in this paper is to use DSMC to study the mixing of two gases in a microchannel. The mixing process is assumed to be complete when the mass composition of each species deviates by no more than ±1% from its equilibrium composition. To enhance the mixing process, we focus on the effects of inlet-outlet pressure difference and the pressure ratios of the incoming CO and N2 streams on the mixing enhancement. The outcome of this study is suitably discussed in the result section.

scholarly journals Development of an Efficient Particle Approach for Micro-Scale Gas Flow Simulations

2009 ◽  
Author(s):  
Quanhua Sun ◽  
Feng Li ◽  
Jing Fan ◽  
Chunpei Cai
Keyword(s):  
Cell Size ◽  
Gas Flow ◽  
Rarefied Gas ◽  
Direct Simulation Monte Carlo ◽  
Gas Flows ◽  
Dsmc Method ◽  
Low Speed ◽  
Micro Scale ◽  
Information Preservation ◽  
Cfd Method

The micro-scale gas flows are usually low-speed flows and exhibit rarefied gas effects. It is challenging to simulate these flows because traditional CFD method is unable to capture the rarefied gas effects and the direct simulation Monte Carlo (DSMC) method is very inefficient for low-speed flows. In this study we combine two techniques to improve the efficiency of the DSMC method. The information preservation technique is used to reduce the statistical noise and the cell-size relaxed technique is employed to increase the effective cell size. The new cell-size relaxed IP method is found capable of simulating micro-scale gas flows as shown by the 2D lid-driven cavity flows.

Vortex-induced rotations of a rigid square cylinder at low Reynolds numbers

2017 ◽  
Vol 813 ◽  
pp. 482-507 ◽  
Author(s):  
Sungmin Ryu ◽  
Gianluca Iaccarino
Keyword(s):  
Cross Flow ◽  
Reynolds Numbers ◽  
Dynamic Responses ◽  
Two Dimensional ◽  
Square Cylinder ◽  
Low Reynolds Numbers ◽  
Pressure Distributions ◽  
Low Reynolds ◽  
Drag And Lift ◽  
Vortex Patterns

A numerical investigation of vortex-induced rotations (VIRs) of a rigid square cylinder, which is free to rotate in the azimuthal direction in a two-dimensional uniform cross-flow, is presented. Two-dimensional simulations are performed in a range of Reynolds numbers between 45 and 150 with a fixed mass and moment of inertia of the cylinder. The parametric investigation reveals six different dynamic responses of the square cylinder (expanding on those reported by Zaki et al. (J. Fluids Struct., vol. 8, 1994, pp. 555–582)) and their coupled vortex patterns at low Reynolds numbers. In each characteristic regime, moment generating mechanisms are elucidated with investigations of instantaneous flow fields and surface pressure distributions at chosen time instants in a period of rotation response. Our simulation results also elucidate that VIRs significantly influence the statistics of drag and lift force coefficients: (i) the onset of a rapid increases of the two coefficients at $Re=80$ and (ii) their step increases in the autorotation regime.

Sign in / Sign up

Export Citation Format

Share Document