One-Dimensional simulation of internal ballistic of a Hybrid Rocket Engine

A one-dimensional code was developed to simulate the performance of hybrid rocket engines. In this code, the conservation equations of mass, momentum and energy are solved in one-dimensional and inviscid form. To validate the code and conduct further experimental studies, an experimental setup was designed and manufactured. The stand had various components, including an experimental-scale motor, an oxidizer feeding system, thrust stand, data acquisition and recording equipment. The repeatability of the results has been proven in it. The simulation results, including the combustion chamber pressure and thrust, were compared with the experimental date and good agreement was achieved. By using the code, flow parameters including speed, pressure, density and mass flow rate ratio (O/F) along the combustion chamber were obtained. The regression rate of the fuel surface in different time periods showed that the fuel regression was not uniform, so that at the beginning of the grain there is a minimal regression, but at a distance of about 0.12 m from the beginning, there is a continuous increase in regression reaching the highest amount, and then decreasing towards the nozzle. This code is a useful tool for analyzing and design of hybrid engines.