Design, Analysis, and Testing of an Additively Manufactured Catalytic Combustor for a Micro-Wave Rotor Turbine

In this paper, an additively manufactured (AM) Inconel catalytic combustor was tested in combination with a microwave rotor turbine with nonaxial channels designed for shaft power extraction. This was done in an open-loop configuration over a range of operating conditions in order to characterize the behavior of the wave rotor and combustor separately. The catalytic combustor data yielded low pressure losses of approximately 1% and provided stable and continuous operation up to outlet temperatures of 900 °C and combustion efficiencies of up to 99%. The data also revealed a high sensitivity to local over-fueling and hotspots that severely reduced service life. This is attributed to the additive manufacturing process producing uneven fuel injector hole sizes that cause uneven fuel mixing upstream of the catalytic reactor. However, it showed that first, it is possible to manufacture and coat an additively manufactured catalytic core. Second, it showed that the design freedom of AM could be used to make catalytic combustors viable in commercial applications.