Liquid-Propellant Rocket Engine Injector Dynamics

The dynamic characteristics of liquid-rocket injectors in the presence of intense combustion-chamber and propellant feed-line oscillations are discussed. Liquid-propellant injectors always function in nonsteady e ow environments and are therefore considered as a dynamic component of an engine. In addition to its main function of injecting propellant and preparing a combustible mixture, an injector simultaneously acts as a sensitive element that may generate and modify e ow oscillations because of its intrinsic unsteadiness and interactions with the combustion-chamber and feed-system dynamics. This paper also addresses nonlinear effects of nonstationary processes occurring in injectors. Various mechanisms for driving self-pulsations in both liquid and gas ‐liquid injectors are summarized systematically. A vital problem of bifurcational unsteadiness of injector operation is considered.