Near-wall gas-droplet flows with liquid-film formation

A self-consistent asymptotic theory of a near-wall aerodisperse flow with the formation of a liquid film due to inertial deposition of liquid droplets on the body surface is constructed. With the reference to the examples of low-speed mist flows near plane and curvilinear solid surfaces, asymptotically different situations are analyzed. The two-fluid equations of the mist flow are solved simultaneously with the equations of the liquid film, on the outer edge of which the distributed mass, momentum, and energy fluxes (found from the solution of the outer problem) are specified. It is shown that depending on the values of governing parameters the flow in the film should be described by either boundary-layer or creeping-flow equations in the layer with a priori unknown thickness. For the film on the frontal surface of a blunt body, the film thickness and the friction and heat transfer coefficients are found numerically. The conditions in which the presence of the film significantly reduces the heat fluxes are determined and the possibility of the realization of steady-state flow regimes in the film is demonstrated. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)