Analysis of a Co-Flow Mixer in Preparation of Combustor-Turbine Matching in a Rotating Detonation Engine

Climate change and consequent emission constraints, paired with an expected increase in air passengers and global energy demand in the next decades, require the development and operation of high-efficiency, low-emission turbomachines in both the energy and aviation sectors. However, over the last decades, gas turbine technology has advanced to a very mature level by optimizing component performance, and it is expected that further improvement would only marginally increase the overall gas turbine efficiency.

To this end, Pressure Gain Combustion (PGC) devices that incorporate an alternative thermodynamic cycle have been under investigation. A notable example is the Rotating Detonation Combustor (RDC), where one or several detonation waves are circulating around a typically annular combustion chamber. A particular characteristic of RDCs is their high-frequency, high-temperature, high-speed exhaust flow that may have a detrimental effect on combustor-turbine coupling in a turbomachinery application.

In an effort to temper this phenomenon, a co-flow mixer is investigated using 1D analytical modeling and a Large-Eddy Simulation (LES). The component entrains subsonic secondary air, aiming at an energy transfer from exhaust to entrained flow.