GEMINI STABILITY IMPROVEMENT PROGRAM (GEMSIP). VOLUME 5. DEVELOPMENT TOOLS

The development is reported of special tools and techniques for pulsing the combustion and hydraulic systems. Three significant developments pertain to the devices for perturbing the thrust chamber, or engine system, to determine its level of stability. One of these is the nondirected pulse charge which is mounted in the combustor and reacts directly on the combustion process. The other two are the single and multiple pulse generators that produce acoustic shocks in the propellant feed system. Their use permits the observation of the possible interaction of feed system disturbances with the combustion in the chamber. The 2-dimensional chamber is another of the devices for observing combustion photographically. The application is described of classical laboratory methods to obtain the natural acoustic resonances of the chamber in several configurations, which were then correlated with the resonances observed with these configurations when firing. The servo control system, is a means to reproduce engine transients, insofar as they are reflected in the thrust chamber, with a simple, low cost, pneumatically pressurized system. Extreme conditions or those of rare occurrence, which cannot be readily produced during engine firing, can be simulated realistically. In addition, multiple data points may be obtained from a single firing, thereby reducing test costs by an order of magnitude.