A Parametric Study of the Effect of Liquid Fuel Entrainment on the Combustion Characteristics of a Paraffin-Based Hybrid Rocket Motor

The interaction between a melting hybrid rocket fuel grain and the combustion processes inside the combustion chamber of a hybrid rocket motor was investigated using a CFD model, ultimately evaluating how this affects the motor’s performance. The motor’s working conditions were simulated by changing the global oxidizer to fuel mass flow ratio, the fraction of the total fuel entrained by the oxidizer, and the size distribution of the entrained droplets. Due to the transport of the fuel droplets the reaction zones are extended farther downstream, which results in an incomplete evaporation and causes significantly lower combustion efficiency comparing to the ideal well-mixed mixture.