Search

The effects of atmospheric pressure, unburned mixture temperature and equivalence ratio on the sec-butanol-air laminar flow combustion were investigated by the smear method and the spherical flame diffusion method. The coupling effects of environmental parameters and equivalence ratio on the unstretched laminar burning propagation velocity and the change value, change rate and ratio of change rate of unstretched laminar burning propagation velocity were mainly analyzed. The results show that the larger the pressure is, the smaller the variation of unstretched laminar propagation velocity is under the coupling of ambient pressure and equivalent ratio. The ratio of change rate of unstretched laminar burning propagation velocity is increased with the increasing of equivalence ratio with downward trend for the equivalence ratio around 1.10. When the equivalence ratio is less than 1.05, the low pressure environment has greater influence on the laminar flow combustion. Under the coupling of ambient temperature and equivalence ratio, the propagation velocity of unstretched flame is more affected by higher ambient temperature when the equivalence ratio is in the range from 0.75 to 1.15. When the equivalence ratio is less than 0.85 or greater than 1.45, the equivalent ratio has great influence on the rate of non-tensile laminar flow combustion. [ABSTRACT FROM AUTHOR]

Based on the constant volume combustion bomb, the effects of equivalence ratio (0.7～1.6), initial temperature (400, 430 and 460 K) and initial pressure (0.1, 0.2 and 0.3 MPa) on butanol-air premixed laminar combustion were investigated by the ball type flame extension method with high speed schlieren photography technology. Several key parameters of laminar combustion of laminar combustion velocity, flame propagation velocity and stretch rate were analyzed in detail. The results show that the stability of flame front becomes worse with the increasing of fuel-air equivalence ratio, while the flame propagation velocity and the laminar burning velocity of unstretched flame are increased firstly with latter decreaseing. Both the flame propagation velocity and the unstretched laminar burning velocity are increased with the increasing of initial temperature, while the stability of flame front is decreased. The unstretched laminar burning velocity and the flame propagation velocity are decreased with the increasing of initial pressure, and the stability of flame front is deteriorated. In addition, the elongation of flame front surface is decreased with the increasing of flame propagation velocity. [ABSTRACT FROM AUTHOR]