Instabilities in a horizontal liquid layer in co-current gas flow with an evaporating interface

The problem of a two-layer system consisting of a horizontal liquid layer in contact with its own vapor is considered.The liquid layer is bounded by a rigid walls from below,and phase change can occur at the interface.The flow of the vapor phase is driven by a constant pressure gradient in the st..

The effect of gravity and shear stress on a liquid film driven in a horizontal minichannel at local heating

The present study is focused on the investigation of gravity effect on thermocapillary deformations in a film flowing under action of co-current gas flow, which creates the tangential force on the gas-liquid interface. The influence of local heating intensity on the heater at a substrate is also investigated. Effects of surface tension, temperature dependent viscosity and thermocapillarity are taken into account. Investigations have shown that gravity has a significant effect on the film deformations and pattern. Decreasing of gravity level leads to a flow destabilization. 3D liquid film pattern noticeably changes in spanwise direction. Increasing of heat flux leads to increasing of liquid film deformations. Dependence of film thinning on heat flux is strongly nonlinear. The most dangerous deformations (regions of minimum film thickness with possible disruption of liquid) take place behind the downstream edge of the heater at any gravity conditions.En ligne: http://www.springerlink.com/content/j207456083166646/info:eu-repo/semantics/publishe

Instabilities in a horizontal liquid layer in cocurrent gas flow with an evaporating interface

The problem of a two-layer system consisting of a horizontal liquid layer in contact with its own vapor is considered. The liquid layer is bounded by a rigid wall from below, and phase change can occur at the interface. The flow of the vapor phase is driven by a constant pressure gradient in the streamwise direction. We have taken into account the effects of buoyancy, thermocapillarity, evaporation, and the dynamics of the vapor phase. A full linear stability analysis is performed using a Chebyshev spectral method. The influences of evaporation effect and the interfacial shear on the Rayleigh instability and the Marangoni instability have been studied. The results show that both the evaporation and the interfacial shear play important roles in the stability of the system