Detonations in fuel-oxygen mixtures

Abstract

A brief literature study was carried out to learn more about detonations, deflagrations, shock waves and critical tube diameters. A comprehensive experimental test rig was assembled based on an earlier test rig. The rig was fitted with stainless steel plugs that had very precisely machined tube diameter to minimize the deviation on this variable. The candidate carried out the machining and experimental rig assembly. More than 50 soap bubble experiments has been performed on various acetylene-oxygen mixtures using four pressure transducers and a high-speed camera. The experimental data has been analyzed to determine if a detonation occurred. Using these data the critical tube diameter as a function of stoichiometric ratio was determined. The results have been compared to earlier experimental data from John Lee [2]. The CJ-detonation velocity has also been calculated and compared with simulation results from the software SUPERSTATE. MATLAB and Excel was used to analyze the data. The Random Choice Method has been used to simulate spherical detonations. It provides a 3D overview of the detonation. This makes is easy to compare it to the pictures from the highspeed camera. By comparing the experimental data and simulation results one can see clear similarities such as the pressure, position and time properties of the detonation, rarefaction wave and the shock wave.