Graves, Charles C.
An investigation was conducted to determine the importance of molecular-scale processes in the overall turbojet combustion process. The effect of oxygen concentration of the inlet oxygen-nitrogen mixture on the combustion efficiency of a single J33 combustor was determined for a range of combustor-inlet pressures, and fuel-flow rates at constant combustor inlet temperature and weight-flow rate. Attempts were made to correlate combustion efficiency with selected fundamental combustion properties and with a simplified reaction-kinetics equation. At a given fuel-flow rate, combustion efficiency decreased at an increasing rate with reduction in oxygen concentration. For the pressures and oxygen concentrations tested, combustion efficiency decreased with a decrease in fuel-flow rate. At a given fuel-flow rate, combustion efficiency correlated with minimum spark-ignition energy, flame speed, and a simplified reaction-kinetics equation. A greater range of combustor-inlet conditions or other types of combustor test will be required to distinguish the most significant correlation.
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