Investigation Into the Adaptation of a Stream Injector for Use on a Liquid Rock Engine

This thesis investigated the properties of a steam injector to see if the concept might be suitable for use on a liquid rocket engine. A steam injector is a device developed in the 1850's and was used to inject feedwater into the boiler on a steam locomotive without any moving parts. The injectors used a small portion of the steam generated in the boiler to increase the pressure of the feedwater to a level higher than the pressure in the boiler. Previous experimenters claim that condensation of steam to water was necessary for an injector to work. This experiment tested injection without condensation using one of AFIT's wind tunnels. Compressed air was used to simulate steam and liquid ethanol was used in place of water. Pressure measurements were taken at points along the tunnel to determine the performance of the tunnel. Results show that this type of injection produces a small pressure rise compared to tests without liquid injection. However, the exit pressure is still lower than the initial pressure. Further testing is recommended to analyze various parameters such as high temperature flows and injector size.