Enhancement of rotating detonation wave dynamics using robust passive acoustic control technologies

Combustion instabilities and secondary wave systems can affect the detonation wave(s) in a rotating detonation combustor (RDC) for augmentors and lead to reduced combustion and thermodynamic efficiencies. To improve the performance of RDCs, it is critical, therefore, to develop practical and robust passive suppression technology to mitigate these acoustic and secondary wave systems. The proposed research effort will (i) design small material samples that provide broadband frequency acoustic absorption, (ii) utilize our in-house expertise in ultra-high-temperature metals/ceramics and additive manufacturing to identify promising materials/designs that can survive in a detonation environment, (iii) characterize the material samples in an impedance tube and shock tube to provide baseline acoustic characterization, (iv) test the most promising small material samples in an in-house modular RDC at Purdue, and (v) test large material samples in the Purdue RDC by replacing the entire RDC outer body (or inner body) with the designed three-dimensional resonator structure and implementing preexisting diagnostics to assess the performance of the passive control technology. This will lead to the development of a design and evaluation process that will prove important for assessing passive acoustic control techniques in RDCs. This will also lead to data on optimal design and placement of passive suppression techniques in the RDC.