A water flow visualization facility was constructed in order to investigate the mixing processes inside of four-inlet ducted rocket engines (DRE) with various flow rates and geometries. The observed flow fields were documented with video and conventional photography so that relationships between various geometric/flow parameters and the flow field behavior could be obtained.

"An investigation was conducted in order to evaluate the static thrust augmentation attainable through the use of a rocket-ejector system with a heated supersonic primary jet. This system consisted of a cylindrical mixing tube in conjunction with a supersonic nozzle having an expansion ratio of 15 to 1. A hydrogen peroxide gas generator was used to provide heated nozzle flow. An ejector with a bellmouthed inlet provided thrust augmentation up to about 18 percent of the primary rocket thrust, whereas the use of a blunt-lip inlet with elliptical profile provided augmentation up to 9 percent. Axial withdrawal of the rocket nozzle from the ejector provided small gains in thrust augmentation."--P.[1]