An experimental study of detonation parameters of liquid fuel drops cloud

In order to understand the mechanism of liquid fuel cloud detonation,the up-and-down method and soot trace technique were used to study the relationship between the cloud detonation parameters(velocity,pressure,critical initiation energy and cell width) and equivalence ratio experimentally with a vertical shock tube.Results indicated that the detonation pressure and detonation velocity of propylene oxide(PO) increased and then decreased smoothly with the rising of equivalence ratio.The critical initiation energy that directly initiated the detonation of hydrocarbon liquid fuel cloud showed a U-shaped curve relation with the variation of equivalence ratios.The optimum concentration was found on the side where the equivalence ratio is over 1.The critical initiation energy was also found closely related to molecular structure and volatility of fuels.IPN and PO had similar critical values and those of alkanes were all larger.Detonation cell sizes of PO at both 25 ℃ and 50 ℃ showed a U-shaped curve.The minimal cell width also lied on the side of rich-fuel(φ1).The detonation reaction of PO at normal temperature is controlled by gas-phase reaction.