Spreading and splashing of liquid film on vertical hot surface by inclined jet impingement

In this paper, the liquid film formed by inclined jet impingement on the vertical hot wall is investigated by a high-speed camera. The effects of the jet velocity (5.5 m/s <= u(0) <= 14.6 m/s, 3804 <= Re <= 10098) and initial wall temperature (25 degree celsius <= T-0 <= 250 degree celsius) on the spreading and splashing of the liquid film are explored. Although the jet velocity and initial wall temperature have little effect on the spreading velocity of the liquid film, the wetting front position and liquid film area increase. For T-0 >= 150 degree celsius, a unique liquid film deflection phenomenon is observed due to the boiling of the liquid film, which results in a substantial amount of splashing. Based on the characteristics of the deflection splashing, three modes are categorized, i.e., annular splashing, banded splashing, and non-splashing. The splashing of the liquid film on the hot surface is owing to the rupture of boiling bubbles, the breakup of surface waves, and the liquid splashing in the boiling zone. The splashing rate of the liquid film is measured, and it is found that an increase in T-0 improves the splashing rate significantly, and the splashing rate even exceeds 70 % at T-0 = 250 degrees C.