Interfacial thermocapillary pressure of an accelerated droplet in microchannels: Part II. Heat transfer formulation

In this companion paper of a two-paper set of thermocapillary pumping studies, a heat transfer formulation is developed with thermal convection in the microchannel and heat conduction in the substrate. Unlike past studies based on a uniform pressure along the droplet/air interface, this article incorporates a more realistic interfacial pressure/velocity coupling to better predict temperature variations along the moving boundary. This improves predictions of thermocapillary forces at the interface, which drive the droplet motion within the microchannel. Close agreement between approximate and numerical predictions of droplet temperature and displacement provide useful validation of the models.