An Original Way to Select and Control Hydrodynamic Instabilities: Microwave Heating

The purpose of this work is the comparison between hydrodynamic behavior observed during water and ethanol evaporation induced by microwave heating and simultaneously under reduced pressure, in order to generalize the specificity of microwave heating in relation to thermal dependency of dielectric loss. Spatial thermal profiles, bulk and interfacial temperatures, as well as the kinetic measurements are presented. Diagrams are proposed in order to give a comparison between the behavior obtained for water and ethanol. A comparison between evaporation induced by reduced pressure and microwave heating is also made. For water the steady processes are preponderant, whereas for ethanol the behaviors quite turbulent. These experimental results have shown a strong stabilization of the liquid bulk for water. For ethanol microwave heating seems a stochastic factor which easily induces turbulence.