Static sensitivity of a spaceplane Ramjet’s thrust and impulse

Abstract

The paper deals with the effect that various perturbations have on values of thrust and impulse of a spaceplane’s ramjet operating on liquid hydrocarbon fuel. Presented is an engineering technique of evaluating the engine’s output characteristics in relation to trajectory parameters, properties of fuel and workflow parameters. Also presented is a summary table of influence coefficients which are used to determine the value and sign of thrust and specific impulse variance caused by certain perturbations. It is demonstrated that excess oxidant ratio has the most profound effect on thrust and impulse characteristics of the ramjet engine, which makes it possible to carry out deep control of the workflow by changing the fuel-oxidizer ratio in the combustion chamber of the engine. Noted is high sensitivity of the output characteristics to changes in trajectory parameters. Recommendations for selecting cruise flight characteristics as well as for increasing the workflow control span are given.