CFD Modeling and Simulation of Combustion in a Hybrid Rocket Engine

In recent years, hybrid rocket engines have played an increasingly important role in space propulsion, thanks to their operational safety and unique functional characteristics. Their restart capability, thrust modulation, structural simplicity, low cost, and flexibility in propellant selection are particularly noteworthy. This makes them suitable for a wide range of applications, such as primary propulsion for launchers, upper stage propulsion and space transportation. In addition, the growing focus on reducing development costs, environmental sustainability, and propulsion system reliability has increased interest in this type of engine. However, they have some limitations, in particular low regression rates and mixing problems, which can lead to incomplete combustion, reduce engine efficiency, and make accurate performance prediction difficult. To address these issues, numerical modeling and CFD simulations are essential tools, capable of describing combustion and grain regression phenomena in greater detail than empirical models alone. In this context, this work focuses on the study conducted by Prof. M. Arif Karabeyoglu on a hybrid rocket engine using high-density polyethylene (HDPE) as fuel and gaseous oxygen as oxidizer. The objective is to analyze the fluid-dynamic and chemical behavior inside the combustion chamber and to evaluate the engine’s performance through a numerical approach.