The Novel Use of the Urbanski-Colburn Valve for Liquid Bi-Propellant Rocket Engines

Liquid bi-propellant rockets have been in use since the early 20th century, but their complexity and risk of bodily harm have kept all but the most advanced and well funded institutions from attempting to design and build them. Liquid rockets are the most cost-effective and efficient source of transporting materials from the earth’s surface to space. Typically, the infrastructure supporting these rockets is just as large, if not larger than, the rocket it is supporting. In this thesis a new, much less complex, and more cost efficient way to fuel a liquid bi-propellant rocket is designed and tested. Through the use of the Urbanski-Colburn valve, a floating injector baffle within the rocket, and nylon fill lines, the total infrastructure surrounding the liquid rocket can be greatly reduced. A 3 inch diameter liquid-bipropellant rocket engine was developed to test this theory. The engine used a mixture of 70% ethanol and nitrous oxide as the fuel and oxidizer. The unlike-pentad injector design provided a 4:1 oxidizer to fuel mixture through the use of orifices and push-to-connect injectors. An igniter was developed to simultaneously burn away the fuel and oxidizer fill lines and begin the combustion process in the combustion chamber. After a year's long test fire campaign, it was found that the Urbanski-Colburn valve could be utilized in the case of liquid bi-propellant rockets. The final test fire of the campaign provided the following results: thrust: 188 pounds; specific impulse: 119 seconds; total impulse 810 pound-seconds.