Abstract
In the liquid propellant rockets, POGO instability can occur through the fluctuation of propellant supply to the engine, the thrust fluctuation, and structural vibration. For the prediction of this instability, it is required to provide unsteady characteristics of the pump represented as the transfer matrices correlating the upstream and downstream pressure and flow rate fluctuations. In the present study, the flow rate fluctuation is evaluated from the fluctuation of pressure difference at different locations assuming that the fluctuation is caused by the inertia of the flow rate fluctuation. The present paper describes the results of experiments performed in some situations. For the validation, transfer functions obtained by experiments are compared with Rubin's result.
