RP-3航空煤油五组分模拟替代燃料的层流燃烧特性

In order to study the laminar combustion characteristics of a five-component surrogate fuel (comprising the mole fraction of 14% n-decane, 10% n-dodecane, 30% isohexadecane, 36% methylcyclohexane and 10% toluene), laminar combustion experiments have been conducted in a constant volume chamber at initial temperature of 390K, 400K and 420K, initial pressure of 0.1MPa and 0.3MPa, equivalence ratios of 0.8~1.5.The propagation law of the flame front, Markstein length and laminar flame speed are obtained by the boundary extraction and measurement of the flame photo. The experimental results were compared with laminar combustion velocity of RP-3 kerosene. The following conclusions can be drawn: An increase in temperature will accelerate the propagation of the spherical flame front. The increase in pressure and the over-rich or over-lean of the mixture is unhelpful to the flame propagation of the five-component mixed fuel. Under the operating condition, the effects of temperature on the flame front instability are not obvious. The Markstein length is reduced with the increase of the equivalence ratio, indicating that the enhancement of the mass diffusion results in an instability of the flame front. The instability degree of the flame front surface obviously increases with the initial pressure increases. The flame front is broken seriously when the initial pressure is higher and a large number of cell-like structures are present. When equivalence ratio is near 1.2, the laminar flame speed can be up to the maximum value, and the flame propagation speed gradually reduces as the equivalence ratio is deviated from 1.2. Compared with the experimental data of RP-3 kerosene, it is found that the laminar combustion velocity of the five-component surrogate fuel is basically consistent with that of the RP-3 kerosene under test conditions.