0
research-article

Comparison of Various Pressure Based Boundary Conditions for Three Dimensional Subsonic DSMC Simulation

[+] Author and Article Information
Niraj Shah

Mechanical Engineering Department, Institute of Technology, Nirma University, Ahmedabad, Gujarat, India - 382481
niraj.shah@nirmauni.ac.in

Abhimanyu Gavasane

Centre for Research in Nanotechnology in Science, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India - 400076
abhimanyug@iitb.ac.in

Dr. Amit Agrawal

Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India - 400076
amit.agrawal@iitb.ac.in

Upendra Bhandarkar

Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India - 400076
bhandarkar@iitb.ac.in

1Corresponding author.

ASME doi:10.1115/1.4037679 History: Received April 22, 2017; Revised August 03, 2017

Abstract

Three dimensional Direct Simulation Monte Carlo (DSMC) has been used to simulate flow in a straight microchannel using an in-house parallelized code. In the present work a comparative study of seven boundary conditions is carried out with respect to time required for achieving steady state, accuracy in predicting the specified pressure at the boundaries, and the total simulation time required for attaining a statistical error within one percent. The effect of changing the Knudsen number, pressure ratio and cross aspect ratio on these parameters is also studied. The presence of a boundary is seen to affect the simulated pressure in a cell when compared to the specified pressure; the difference being highest for corner cells and least for cells away from walls. All boundary conditions tested work well at the inlet boundary however similar results are not obtained at the outlet boundary. For the same cell size, the schemes that employ first- and second-order corrections lead to a smaller pressure difference compared to schemes applying no corrections. The best predictions can be obtained by using first-order corrections with finer cell size close to the boundary. For most of the simulated cases, the boundary condition employing the characteristic scheme with non-equilibrium effect leads to the minimum simulation time. Considering the non-equilibrium effect, prediction of inlet and outlet pressures and the speed of simulation, the characteristic scheme with non-equilibrium effect performs better than all the other schemes, at least over the range of parameters investigated herein.

Copyright (c) 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In