A Study of Injection Processes for Liquid Oxygen and Gaseous Hydrogen in a 200-pound-thrust Rocket Engine

Characteristic velocities of six single-element injectors that separately varied propellant spreading and mixing were measured over a range of oxidant-fuel weight ratios of 2 to 7. Hydrogen inlet temperature was -320 degrees F. Injectors that both mixed and spread the propellants had the highest characteristic-velocity efficiency. Spreading of either propellant produced about the same increment efficiency. The increase in efficiency due to mixing was relatively small. With similar injectors, oxygen-hydrogen required about 0.2 to 0.5 of the combustor volume of oxygen-heptane for the same efficiency

NACA Research Memorandums

Characteristic velocities of six single-element injectors that separately varied propellant spreading and mixing were measured over a range of oxidant-fuel weight ratios of 2 to 7. Hydrogen inlet temperature was -320 degrees F. Injectors that both mixed and spread the propellants had the highest characteristic-velocity efficiency. Spreading of either propellant produced about the same increment efficiency. The increase in efficiency due to mixing was relatively small. With similar injectors, oxygen-hydrogen required about 0.2 to 0.5 of the combustor volume of oxygen-heptane for the same efficiency

NACA Research Memorandums

From Introduction: "In response to the ever-increasing need for high thrust augmentation, an investigation was conducted that had as its primary objective the attainment of maximum exhaust-gas temperature and thrust (ref. 1). The investigation reported herein was therefore conducted to ascertain the operational limits of the most promising high-temperature afterburner design of reference 1 and to determine its performance over a wind range of flight conditions.

NACA Research Memorandums

From Summary: "An investigation was conducted at simulated high-altitude flight conditions to evaluate the use of compressor evaporative cooling as a means of turbojet-engine thrust augmentation. Comparison of the performance of the engine with water-alcohol injection at the compressor inlet, at the sixth stage of the compressor, and at the sixth and ninth stages was made. From consideration of the thrust increases achieved, the interstage injection of the coolant was considered more desirable preferred over the combined sixth- and ninth-stage injection because of its relative simplicity.

NACA Research Memorandums

Report presenting an experimental investigation to determine the thrust augmentation possible by the injection of liquid ammonia into the compressor inlet of an axial-flow-type turbojet engine. Results regarding the selection of coolant, cooling with liquid ammonia, engine performance, and operating experience are provided