| 论文简介 |
Experiments were conducted in a constant volume bomb filled with iso-octane/n-butanol blends-air mixtures over a wide range of n-butanol blending ratios, equivalence ratios and initial pressures. High speed schlieren photography was used to measure the critical radius for the onset of flame front instability. Results show that for given n-butanol blending ratio, cellular instabilities appear earlier and the critical Peclet number which represents the onset of instability is decreased with the increase of initial pressure and equivalence ratio. Under fuel-rich conditions, the critical Peclet number increases with the increase of n-butanol blending ratio. Theoretical calculation of the critical Peclet number was also conducted to interpret the effects of n-butanol on the flame front instabilities of the blends. Results show that rich mixture conditions, with the increase of n-butanol blending ratio, the overall activation energy of the mixtures is decreased and thus the thermal-diffusional instabilities are suppressed. While under fuel-lean conditions, the thermal-diffusional instabilities are favored. As a consequence, with increasing n-butanol blending ratio the critical Peclet number is expected to be decreased under fuel-lean conditions and increased under fuel-rich conditions. |
(创新港)
