Using a super-critical platform and a constant volume combustion bomb system

gasoline with different critical states

including low subcritical

subcritical and supercritical state gasoline was injected respectively into a supercritical environment

and then the spray characteristics of the gasoline obtained from the schlieren imaging system were compared with those in the normal temperature and pressure environment. Results show that in the supercritical environment and at the same injection timing

as the injection temperature rises

the spray penetration of the single-hole injector increases first and then decreases steadily

but it is always increasing for supercritical state gasoline. The spray area continues to expand

but for the subcritical state gasoline

it fluctuates and falls after reaching its peak. And as the injection temperature rises

the spray penetration of the five-hole injector first rises steadily

and then drops rapidly below the initial value. The spray area increases first and then decreases slowly for subcritical state gasoline or falls after reaching its peak for supercritical state gasoline. In addition

under the same spraying conditions

the development of spray pattern in the supercritical environment is significantly different from that in the normal temperature and pressure environment. Due to the interaction of the spray and environment in the supercritical environment

the collapsing phenomenon and the micro-explosion of the bubble will dominate the development of the spray. The variation of the spray penetration and spray area with time will be much smaller in the normal temperature and pressure environment.