Quantifying Deflagration Losses in Rotating Detonation Combustors

This work introduces a new method to determine combustion efficiency in rotating detonation combustors (RDC) that can be evaluated from thrust stand measurements, which is derived using a conservation of energy statement. The method is applied to three RDC datasets acquired at various combustor lengths, air mass flowrates, and equivalence ratios. Measurements reveal combustion efficiencies between 50% and 70%, with uncertainties ranging from 15% - 30%. These measurements were then integrated with a reduced-order model for an RDC to further provide insights into energy conversion processes and the spatial distribution of heat release. Results show that the heat released by the detonation wave increases quadratically with the CJ-normalized wave speed while deflagrative heat release decreases linearly.