Plasma spray produced coatings for boiling heat transfer enhancement

Efficiency of plasma sprayed porous coatings by the enhancement of heat transfer for boiling F-113 and its influence on nucleate boiling burnout and hysteresis phenomena were investigation. Copper, aluminum and bronze coatings by means of low-temperature plasma jet were sprayed in the air. After heat transfer experiments porous coating thickness, porosity and mean pore radius were measured. The influence of these parameters on heat transfer processes for boiling freon F-113 is analyzed on the basis of a theoretical model and experimental data. It is shown that the optimum values from the viewpoint of heat transfer intensification exist for these three parameters. At the same time the optimum of each parameter depends on two other parameters and heat flux density.