This paper reexamines the hybrid rocket in light of several important unanswered questions regarding its performance.The well-known heat transfer limited burning rate equation is quoted, and its limitations are pointed out. Several inconsistencies in the burning rate determination through fuel depolymerization are explicitly discussed. The resolution appears to be through the postulate of (surface) oxidative degradation of the fuel.Experiments are initiated to study the fuel degradation in mixtures of nitrogen/oxygen in the 99.9%/0.1% to 98%/2% range. The overall hybrid combustion behavior is studied in a 2"diameter rocket motor, where a PMMA tube is used as the fuel.The novel results of this study include detailed, real-time infrared video images of the combustion zone.Space-and time-averaged images give a broad indication of the temperature reached in the gases.A brief outline is shown of future work. which will specifically concentrate on the exploration of the role of the oxidizer transport to the fuel surface. and the role of the unburned fuel that is reported to escape below the classical timeaveraged boundary-layer flame.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.