乙醇汽油/空气自着火特性的激波管试验

The auto-ignition characteristics of the mixture of ethanol-gasoline at the pump and air under the conditions of high temperature and low pressure were studied by using reflected shock waves in an atomized shock tube. The ignition delay time, ignition pressure and OH spontaneous light intensity of the ethanol-gasoline/air mixture within temperature range of 1 100-1 750K, pressure range of 0.1-0.65 MPa and equivalence ratio φ of 0.2-2.5 were measured. The effects of φ, ignition temperature and pressure on auto-ignition characteristics of the mixture were analyzed. The results show that under the condition of high temperature, the ignition delay time of the ethanol- gasoline/air mixture lengthens with the increase of the equivalence ratio and the correlation between the logarithm of the ignition delay time and the reciprocal ignition temperature is linear distribution under different pressures. The ignition delay time satisfies the Arrhenius relation and has a higher dependent on pressure within the lowpressure range. The mixture deflagration occurs violently when the equivalence ratio is 1.0 and ignition temperature within 1 300-1 430 K. At this time, the OH spontaneous light intensity instantly reaches the peak value and then drops sharply. When the temperature increases, the OH spontaneous light maintains a higher intensity level for a longer time, and the deflagration pressure peak value decreases, close to the equal pressure combustion.