58802 - Carbon and Hydrocarbon Particle Seeding in Air-Breathing Rotating Detonation Engine 

Within the power generation community, the Rotating Detonation Combustor (RDC) is only growing in popularity. Given its pressure-gain performance, its relatively simple mechanisms and manufacturing, and its flexible operating conditions, it has the potential to revolutionize power generation. However, the RDC is still considered new, with a low technological readiness level in all of its applications, and many of its gains are still to be seen in its active research community across the globe. Meanwhile, the introduction of solid particles into a flow, known as seeding, has been experimented with for conventional combustion systems for the sole purpose of diagnostics for particle image velocimetry (PIV), with little research on the effects of the seeding on performance. It is theorized that the heat release of a solid particle could accelerate reaction burn times, increase the usable temperature of the combustor in a gas turbine engine, and overall, create more energy to be extracted from a power generation system. However, combustion physics of solid particles in a gas flow are still largely uncharacterized or unknown. Furthermore, within the scope of a detonation in a RDC, there is no literature on the subject. With this investigation into solid particle detonation, a RDC rig at the University of Central Florida (UCF) was developed, based on the 6 inch air-breathing RDC design from Air Force Research Laboratory (AFRL), tested by National Energy Technology Laboratory (NETL). An in-depth heat transfer analysis of solid particle burning in a detonation is still being conducted at UCF to better understand when and how the particle reacts from a detonation wave passing. Initial results have prompted preliminary selection for particles to be tested for seeding, based on a variety of parameters from molecular heat release to average particle diameter. Some particles selected have also been chosen for their sustainable properties as green particles, created from renewable sources. The solid particles: confectioners (powdered) sugar, peanut flour, cornstarch, and coal (carbon black) were inserted into a gaseous Hydrogen/Air mixture RDC by an in-line particle seeder. By back-end imaging, the particles were realized for their effect on the detonation by the detonation wave speed, and their burning process was analyzed in side-end imaging from the RDC exhaust plume.