If I pour water in a glass to make a cup of tea, I noticed that if the water that comes out of the kettle is very hot, almost no water is spilled. If the water is cold though, much more water is spilled. The water streams over the surface of the kettle. Why does the higher velocity of the water molecules cause them to stick less to the kettle?
Quoting from the article:
When the fluid flows over the heated curved surface in proximity of the curved surface as the temperature of the curved surface increases, dynamic viscosity of the fluid at the vicinity of the wall is increasing with respect to the fluid which is far from the curved surface. Then the thermal heat capacity of the fluid near to surface is increasing, and then consequently, the Prandtl number of the fluid near the curved surface is increasing. In this way the momentum boundary layer would be increasing resulted in the decreased adhesion angle.
The second mechanism can also be given by assuming the constant Prandtl number. Increasing the jet velocity, the thermal gradient near the surface is increasing and the thermal boundary layer would be decreased and consequently the momentum boundary layer would be decreased. In this way the adhesion angle would be increased. Consequently, the observed earlier detachment happens by the effect of the complex equilibrium of the above-mentioned effects.
The conclusion is that
Thermal effect on the flow has been analyzed as shown in table 1. Increment of the temperature of curved surface induced the earlier detachment of the jet.