| Abstract:In order to research the influence of different gas parameters and ambient pressure on air-assisted spray. In this study, spray characteristics was investigated under various air duration, air pressure and ambient pressure in a constant volume vessel by high-speed photography, with specifically interest in macroscopic spray characteristics. Penetration and spray area was used to quantitative analysis spray characteristics. Under different test conditions the results show that two-stage development of air-assisted spray penetration is observed and the spray area exhibit linear increase. Increase air pressure or decrease ambient pressure is beneficial to enhance the spray penetration and spray area, while air duration has little influence on penetration and spray area. The spray shape of different air pressure and air duration were almost the same, with only slight difference. However spray shape is greatly affected by ambient pressure, at low ambient pressure, the spray shape is a "spindle" shaped, while at high ambient pressure, it presents an "anchor hook" shape and a "cone" shape. With the increase of ambient pressure, the thin region of spray began to decrease gradually and disappeared, under high ambient pressure the spray is mainly the core region. |