Gas-flow animation by unsteady heating in a microchannel

We study the flow-field generated in a one-dimensional wall-bounded gas layer due to an arbitrary small-amplitude time variation in the temperature of its boundaries. Using the Fourier transform technique, analytical results are obtained for the slip-flow/Navier–Stokes limit. These results are complemented by low-variance simulations of the Boltzmann equation, which are useful for establishing the limits of the slip-flow description, as well as for bridging the gap between the slip-flow analysis and previously developed free-molecular analytical predictions. Results are presented for both periodic (sinusoidal) and nonperiodic (step-jump) heating profiles. Our slip-flow solution is used to elucidate a singular limit reported in the literature for oscillatory heating of a dynamically incompressible fluid.