The linearized frequency models for oxidizer-rich preburner were developed to analyze the preburner pressure dynamic response under the propellant flow rate disturbance.The validity of the models and calculation method were confirmed by comparing the results with the test data from references.Using the adiabatic flow model which considered entropy wave during the low frequency range

the frequency responses of preburner pressure under kerosene and liquid oxygen flow rate disturbance were compared respectively

and the result shows that kerosene flow rate disturbance causes higher entropy wave amplitude.The influence rules of the dimensionless slope of combustion temperature and mixture rate as well as pressure ratio of the turbo and combustion time lag on the preburner frequency characteristics were also analyzed.When the concerned frequency range is wide

the distributed parameter model considering the acoustic effect should be used

because the model not only contains the adiabatic flow model during the low frequency range

but also can reflect the longitudinal acoustic oscillation.