The use of a 3-d printed, polymer matrix containing pulverized fuel in a hybrid rocket

A commonly cited drawback of hybrid rockets is the low regression rate of the solid fuels typically employed. Numerous methods have been used to enhance this regression and thereby increase the thrust produced. In this paper, a new approach is described, using an open-cell, polymer matrix, with the void spaces filled with pulverized fuel. Appropriately chosen fuels will not melt and clump, and thereby will provide a high surface area and rapid burning when the individual polymer cells rupture and discharge their contents into the combustion chamber. Since each cell is small, the pulverized fuel enters the combustion chamber at a reasonably constant rate, providing rapid, but steady combustion. In this study, thrust stand tests were conducted and validated the concept, showing total impulse values substantially higher than those achieved using conventional, solid polymer grains.