Control over the formation of structures in a heated liquid film

An experimental investigation is performed of the impact made by artificial disturbances on the formation of structures under conditions of flow of water film on a vertical plate with a heater. The fluorescent method is used for measuring the film thickness. It is found that artificial disturbances on the surface of liquid film may cause a significant variation of the spacing between jets, and the scenario of evolution of wave pattern depends on their intensity. Artificial disturbances on the film surface cause the spacing between jets to decrease from values corresponding to the thermocapillary-wave mode of formation of jets to values close to those of spacings typical of the thermocapillary mode. In so doing, the spacing between jets may be varied at higher values of Reynolds number than is the case in the thermocapillary mode. It is demonstrated that it is possible to control the formation of structures on the surface of a heated film of liquid, and the conditions of maximal effect of artificial disturbances are determined.