Experimental investigation of gasoline spray vaporization behaviors under various ambient conditions

In terms of spray vaporization visualization, effects of ambient temperature (394-516 K) and ambient pressure (0.1-3.8 MPa) on multi-hole gasoline spray macroscopic characteristics has been investigated separately via optical diagnostics. Schlieren method was adopted to visualize vapor phase fuel at high ambient temperature. Laser sheet optical patternation provided us with cross-section perspective to verify results in schlieren images and acquire additional information like plume distribution. The results show that vaporization process will be promoted by high ambient temperature due to enhanced heat transfer between spray body and surrounding gas. The effects of ambient pressure on spray evolution possess different inner mechanisms with ambient temperature variation. In low ambient temperature, axial evolution indicated by vapor tip penetration will be restricted by high ambient pressure, whereas radial expansion indicated by spray angle will be facilitated. For atmospheric ambient pressure in high ambient temperature, spray collapse will appear due to enhanced vaporization of single plume and intensified jet-to-jet interaction. Moreover, because of inhibited vaporization of light component in high ambient pressure, vaporization model will transfer from distilled-like vaporization to co-vaporization, indicated by homogeneous vapor phase distribution.