Numerical Analysis on combustion inside RD-108 Rocket Nozzle

Understanding the combustion process that happens in a liquid propellant rocket engine is a challenge, in part because of the turbulent nature of the process. In this study, effort is made to gain more knowledge on the subject by studying the characteristics of combustion inside the rocket nozzle and aspects of performance and efficiency of a rocket. These efforts are made possible by conducting a numerical simulation on RD-108 rocket engine using modern simulation software that allows the study of a wide range of subjects in a short time. The simulation is conducted using Computational Fluid Dynamics technique, specifically 2-Dimensional Navier Stokes equation. Result shows that the most stable and ideal simulation of combustion process in RD-108 rocket nozzle occurs when using the default size of combustion chamber, coarse structural grid, k-ε turbulent flow model with re-normalization group, kerosene-air propellants, hybrid initialization and a specific setting to run calculation. A standard model, which contains all of the aforementioned properties is then used to calculate the thrust force and specific impulse. Result shows that while the thrust force deviates from experimental data by over 30%, the specific impulse value has a deviation of 4.46%, verifying the accuracy of the data. Result also shows that the thrust force and specific impulse in hydrogen-air model is more than than kerosene-air model, in agreement with the scientific literature