Nonlinear filtering for low-velocity gaseous microflows

Carolyn R. Kaplan
2001 AIP Conference Proceedings  
Gaseous flows in microfluidic devices are often characterized by relatively high Knudsen numbers. For such flows, the continuum approximation is not valid, and Direct Simulation Monte Carlo (DSMC) is an appropriate solution. However, for low-velocity flows, where the fluid velocity is much smaller than the mean molecular velocity, large statistical fluctuations in the solution mean that the features of the flow may be obscured by noise in the solution. In this paper, we evaluate a method for
more » ... ate a method for numerically simulating low velocity microflows, in which we use a high-order, nonlinear monotone convection algorithm as a filter to extract the solution from the noisy DSMC calculation. We test the filtering method on a high-velocity microchannel flow problem, for which we know the correct DSMC solution, and show that the filtered and correct DSMC solutions are qualitatively similar and follow the same trends. We then apply the filter to a low-velocity microchannel flow and compare the results with an analytical continuum solution using slip-wall boundary conditions. Results indicate that the filtering operation successfully removes the large statistical fluctuations, reduces computational time, and makes it feasible to do low-velocity microflow calculations. CP585, Rarefied Gas Dynamics: 22 nd International Symposium, edited by T. J. Bartel and M. A. Gallis 2001 American Institute of Physics 0-7354-0025-3 472
doi:10.1063/1.1407598 fatcat:jgh2cmvqbjh7rmygeltftwc5ze