MSM 99
MSM 99
Technical Proceedings of the 1999 International Conference on Modeling and Simulation of Microsystems

Computational Methods for Microfluidics Chapter 15

Scaling Issues for Calculations of Low-Velocity Gaseous Microflows

Authors: C.R. Kaplan and E.S. Oran

Affilation: Naval Research Laboratory, United States

Pages: 506 - 509

Keywords: direct simulation Monte Carlo, microflows, high Knudsen number flows

Gaseous flows in microfluidic devices are often characterized by relatively high Knudsen numbers, Kn. For such flows, the continuum approximation is not valid, and Direct Simulation Monte Carlo (DSMC) is an appropriate solution method. However, for slow flows, where the fluid velocity is much smaller than the mean molecular velocity, the statistical fluctuations in the solution cause the features of the flow to be lost in the noise. In this paper, we evaluate a method for solving low-velocity microflows by scaling the temperature of the fluid such that the molecular thermal velocity is on the same order of magnitude as the fluid velocity. We present an analysis of this scaling method, and show how modification of the fluid temperature affects the collision dynamics.

Scaling Issues for Calculations of Low-Velocity Gaseous Microflows

ISBN: 0-9666135-4-6
Pages: 697