Various Boundary Condition Implementation to Study Microfilters Using DSMC Simulation

2010 ◽  
Author(s):  
Masoud Darbandi ◽  
Hassan Akhlaghi ◽  
Abolfazl Karchani ◽  
Soheyl Vakili
Keyword(s):  
Boundary Condition ◽  
Monte Carlo ◽  
Gas Flow ◽  
Direct Simulation Monte Carlo ◽  
Direct Simulation ◽  
Dsmc Method ◽  
Uniform Distributions ◽  
Dsmc Simulation ◽  
Flow Through ◽  
Simulation Monte Carlo

In this study, we present a vast boundary condition treatment to simulate gas flow through microfilters using direct simulation Monte Carlo (DSMC) method. We examine the effects of different boundary condition treatments on the density, pressure, and velocity distributions and suggest the best conditions to simulate gas flow through microfilters. We also refine the effects of upstream and downstream locations on the solution. The results show that uniform distributions can be achieved if we apply the inlet/outlet boundary condition at appropriate upstream and downstream distances. We also show that all the suggested boundary conditions suitably predict the pressure drop coefficient factor across the filter. To evaluate the current results they are compared with some available empirical formulations.

DSMC Simulation of Ion Generation in Atmospheric Air

2003 ◽  
Author(s):  
W. Zhang ◽  
T. S. Fisher ◽  
D. J. Schilitz ◽  
S. V. Garimella
Keyword(s):  
Monte Carlo ◽  
Direct Simulation Monte Carlo ◽  
Direct Simulation ◽  
Dsmc Method ◽  
Atmospheric Air ◽  
Section Data ◽  
Ion Generation ◽  
The Monte Carlo Method ◽  
Dsmc Simulation ◽  
Simulation Monte Carlo

The generation of ions in air has several useful applications, such as electrohydrodynamic (EHD) pumping, air purification and isolation breakdown prevention. In this paper, ion generation processes in atmospheric air are simulated using a Direct Simulation Monte Carlo (DSMC) method. Details of the collision model are discussed. A C++ code is developed to implement the Monte Carlo method with cross-section data compiled from the literature. Self-sustaining discharge and ionization can be reproduced in the simulation under sufficient voltage bias, and the associated trends obtained are similar to those predicted by Paschen’s curve for a parallel-plate configuration.

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.

Direct Simulation Monte Carlo Method for the Simulation of Rarefied Gas Flow in Discrete Track Recording Head/Disk Interfaces

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Maik Duwensee ◽  
Frank E. Talke ◽  
Shoji Suzuki ◽  
Judy Lin ◽  
David Wachenschwanz
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Gas Flow ◽  
Rarefied Gas ◽  
Direct Simulation Monte Carlo ◽  
Direct Simulation ◽  
Rarefied Gas Flow ◽  
Recording Head ◽  
Discrete Track ◽  
Simulation Monte Carlo

The direct simulation Monte Carlo method is used to study rarefied gas flow between an inclined plane slider bearing and a nanochannel representing one groove in discrete track recording head/disk interfaces. The forces acting on the slider are determined as a function of slider pitch angle, disk velocity, groove pitch, width, and groove depth. It is found that the influence of manufacturing tolerances on slider forces is smaller for deep and wide grooves than for the case of shallow and narrow grooves.

Gas Properties Effects in Microchannel Studies Using Direct Simulation Monte Carlo

2010 ◽  
Author(s):  
Masoud Darbandi ◽  
Abolfazl Karchani ◽  
Hassan Akhlaghi ◽  
Gerry Schneider
Keyword(s):  
Heat Transfer ◽  
Monte Carlo ◽  
Slip Flow ◽  
Direct Simulation Monte Carlo ◽  
Direct Simulation ◽  
Polyatomic Gases ◽  
Flow And Heat Transfer ◽  
Flow Through ◽  
Simulation Monte Carlo ◽  
Gas Properties

This paper concern is to study the gas properties effect in flow and heat transfer behaviors through microchannels using the direct simulation Monte Carlo method. The flow is rarefied and supersonic. The channels are investigated at two different inlet boundary conditions. The collision process is modeled using the NTC (no-time-counter) scheme. The VHS model is chosen to simulate collision between particle pairs. The study is provided for many different gases including nitrogen, helium, and oxygen. The Knudsen number is chosen in a manner to provide slip flow through the channel. The results show that the heat transfer from the wall is lower for heavier gases. A comparative study among the monatomic, diatomic, polyatomic gases shows that the heat transfer rate is lower for the polyatomic gases. The result shows that, the heat transfer from the wall is lower for the heavier gases than that for the lighter gas. For a fixed Mach number, the heat transfer from the wall decreases as the molecular diameter increases.

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