The Effect of Oxygen Concentration on Ignition of Fuel Spray in Low-Pressure Air Flow

Abstract

Further experimental research has been carried out on the ignition improvement by oxygen addition in a small pilot combustion chamber taken from an existing aeroengine. Both uniform mixture method and local oxygen injection method have been investigated. The results show that oxygen addition improves low-pressure ignition performance significantly. Local oxygen injection makes much better use of oxygen added. Experimental results show low evaporation percentage of fuel spray responsible for the poor ignition performance. Based on thermal ignition theory, a semianalytical equation has been obtained to predict the relative enlargement of maximum ignition velocity by oxygen addition, the equation can correlate experimental data very well. To form a stagnant region with suitable oxygen concentration is the most important factor in the design of ignitor with oxygen addition.