566 / 2019-01-19 11:39:36

Experimental study on fuel spray impingement process against metal surface with different wettabilities

Fuel Spray; Wettabilities; Entrainment Height; Spreading Radius; Near-wall Mixture Concentration

全体主题 > 燃料利用与化学循环技术

In this study, the development process of the fuel sprays after hitting the wall was experimentally studied in order to explore new optimization and design methords for future combustion chamber of intrnal combustion engine. The wettability of certain metal surfaces were modified with bionic surface treatment. Different fuel sprays including diesel spray and n-butanol spray were managed impinging onto the surfaces of metal materials with different wettability and temperatures, at different environmental pressures. The results showed that under an atmosphere temperature and pressure, both the entrainment height and spreading radius of different fuel sprays increased as the surface wettability decreased. For all the fuels tested, the spreading speed along the wall and rebound speed against the wall were gradually decreases with an increase of the surface wettability. After hitting the wall, the concentrations of the air-fuel mixture in the near-wall region were also measured; and differences could be observed when the wettability of the walls is different. Other than the wall wettability, the near-wall mixture concentration was also greatly affected by the physi-chemical properties of the fuels itself, such as the boiling point, viscosity and surface tension, etc. With the increase of the surface temperature and the environmental pressure, the influences of surface wettability to the post-impingment development of the fuel spray and formation process of the near-wall mixture were gradually weakened. Among the three factors affecting the gas mixture concentrationin in the near wall area, the influence of wall temperature was most significant. As the wall temperature increased, the influence of the other two factors became unconspicuous.