DETERMINATION OF HEAT TRANSFER COEFFICIENT DISTRIBUTION IN MICRO-RDC USING MEASURED WALL TEMPERATURES

Abstract

Rotating Detonation Combustors (RDCs) have recently garnered significant attention in aero combustion research due to their potential efficiency advantages over conventional deflagration-based systems. Specifically, small-scale RDCs, such as Micro-RDCs, have proven to be promising alternatives as thrusters or auxiliary power generators. Moreover, their compact dimensions and simple design make Micro-RDCs ideal research platforms for detailed investigation of detonation dynamics and cooling strategies. However, integrating RDCs into gas turbine systems remains challenging, with thermal management emerging as a critical bottleneck due to the extreme heat flux generated during detonation. Heat transfer in RDCs is still an under-explored topic. This work presents a methodology based on an inverse approach to determine the heat transfer coefficient (HTC) distribution along a RDC annulus flow path using measured wall temperature maps on the external surface. An infrared (IR) camera was employed to capture the evolution of the outer wall temperature during detonation tests. The inverse method, in combination with FEM simulations, enabled the retrieval of the spatial distribution of the heat-transfer coefficient (HTC) within the combustion chamber, as well as the heat flux through the outer wall during the detonation transition process. A series of experiments were conducted under varying operating conditions, providing a detailed understanding of the heat flux distribution on the liner and revealing the system's sensitivity to thermal loads. This approach allows for a thorough assessment of the thermal environment, offering key insights for optimizing RDC design and improving thermal management strategies in practical applications.