Experiment study on adhesion dynamic characteristics of droplet impacting on an inclined heated surface

The behaviors and mechanisms of droplet impact on an inclined heated surface is of great importance. In this work, an experimental platform for the droplets impact on the surfaces with different inclined angles and temperatures was established to study the various impact patterns and dynamics. The impact pattern, sliding distance, lengths at the leading and trailing edge points and maximum spreading factor were studied in detail. The results show that the impact patterns were classified as adhesion, splash, rebound and breakup patterns. In the adhesion pattern, a sliding distance model was developed based on Newton's second law and force analysis that considered the viscous, adhesion and gravitational forces for different angles. Larger angle promotes length of the leading edge point, inhibits length of the trailing edge point. Higher temperature suppresses the length of the trailing edge point by boiling. In addition, a model for the maximum spreading factor of the inclined surface was developed by combining a spreading prediction mode with an energy conservation equation, which incorporates kinetic, surface and dissipation energies. An increase in the normal Weber number suppresses the maximum spreading factor. Temperature has a different effect on the maximum spreading factor depending on the normal Weber number.