Prediction of Time Variation of Ballistic Parameters For a Swirling-Oxidizer-Flow-Type Hybrid Rocket Engine using Burning Data

For hybrid rocket engines, there are some unique relationships between the parameters, such as the fuel regression rate, oxidizer mass flow rate, equivalence ratio and so on, which determine the burning properties. These relationships are strongly related to the engine performance. Our final goal of this study is to establish the optimum design method which considers the engine performance of hybrid rocket engines for practical hybrid rockets varying with time. In this paper, we focused on the time variation of ballistic parameters. First, we established the calculation method which well simulates the burning condition of the swirling-oxidizer-flow-type hybrid rocket engine. Next, we predicted the time variation of the burning properties and ballistics parameters using this calculation method and some experimental burning data. The simulation results showed little difference in the time variations of the combustion pressure and thrust from the experiment. The simulated values of the engine efficiencies of Isp, C* and CF obtained well agreed with those experimentally. The simulation method proposed here is appropriate for predication of time variation of ballistic parameters and may be useful as a design tool for hybrid rocket engines.