The 13-moments method for heat transfer in gas microflows

What is it about?

In this work, the heat transfer within MEMS devices materialised by a cavity is envisaged. The problem is studied using the Grad’s 13-moments and the Navier–Stokes and Fourier feld of equations (NSF), with frst order of slip and jump boundary conditions, compared to the direct simulation Monte Carlo (DSMC) results. A Maxwelllian gas is assumed to be confned in a cavity at the environmental temperature. The cavity is taken to have a hot chip, an adiabatic one while the two others are taken to the environmental temperature. The 13-moments solutions are in accordance with DSMC predicting, besides the classical hot to cold vortices, two additional counter-rotating ones exchanging energy with the two cold walls, which are not predicted by the continuum-based model. The Knudsen number growth, gas rarefaction degree, affects the vortices by pushing the classical ones towards the centre and hot plate, while strengthening the others.

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