Detonation Propagation in Mixtures Containing Exhaust Gases

View Video Presentation: https://doi.org/10.2514/6.2023-0348.vid Detonation propagation in rotating detonation engines does not occur in a uniform, quiescent mixture. In addition to gradients in pressure, temperature, velocity, and mixture composition; products from previous detonation cycles can mix with the fresh reactants, diluting the reactants and potentially inducing parasitic deflagration. The Air Force Research Lab has designed an experiment to study the effects of product recirculation and parasitic deflagration ahead of a detonation wave. This is achieved by having two detonation channels side by side with small holes between them. A detonation is initiated in one of the channels which causes detonation products to inject and mix into the other detonation channel. A short time later, a detonation is initiated in the second channel. Experimental data show that the addition of hot exhaust gases increases the second detonation’s velocity, and this velocity increment correlates with how much exhaust gas is present at the time that the second detonation reaches it. This paper goes over the experimental design, results, and analysis of the data collected. Comparison to previous theoretical work and experimental RDE data is also performed.