Receding Dynamics of Jatropha Straight Vegetable Oil Drops Impacting a Heated Surface

Abstract

Straight vegetable oils have a huge potential to minimize the dependence of the automobile and energy sectors on conventional fossil fuels. In the present study, the impact of a single drop of Jatropha straight vegetable oil on a stainless steel surface is investigated for various surface temperatures. The effects of the impact velocity and the surface temperature on both spreading and receding of the drops are examined. Experiments are conducted at nine surface temperatures and four impact velocities. The impact morphology reveals that the minimum surface temperature required for the initiation of the bubble nucleation is independent of the Weber number or the drops’ initial kinetic energy. The Leidenfrost point is not observed even at the highest temperature tested for the entire Weber number range. The average receding velocity is not found to depend on Weber number at a given surface temperature in the film evaporation and the film boiling regime. It increases initially with surface temperature up to 280 °C and remains constant for further higher surface temperatures. Although the receding distance increases monotonously with the surface temperature, the average receding velocity does not increase beyond 280 °C.