A DSMC investigation of gas flows in micro-channels with bends

Abstract

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Direct simulation Monte Carlo method for gas flows in micro-channels with bends with added curvature

“…As in work of White et al [2], the straight channel length L is 15 ȝm and its width B is 1 ȝm. Concequently the bends and round offs are added in a way that the channels volume and surface area do not change.…”

“…Since DSMC is the dominant method for solving rarefied gas flows, there has been many DSMC studies dealing with straight microchannel gas flows [2,3,7,8,9]. However, there is significant lack of data concerning microchannels of more complex geometry.…”

“…It is recommended that the cell size in DSMC is less than mean free path of the gas molecules. However, it is possible to use elongated cell sizes in the streamwise direction of microchannel flows [2], where macroscopic gradients are relatively small. In channels with bend, the corner region is meshed with cells of sizes smaller than mean free path in both directions.…”

“…Similarly, the time step should be a fraction of the mean collision time of the gas molecules. [2] It is the generally low value of the time step that represents the greatest drawback for DSMC with respect to the computational effort needed to arrive to the converged solution.…”

“…However, there is significant lack of data concerning microchannels of more complex geometry. Nevertheless, White et al [2] used DSMC and carried out series of numerical simulations for flow in microchannels with bends. No work on flow in microchannels with bend with added curvature has been found in available literature.…”