Theoretical and Experimental Consideration of the Continuous Rotating Detonation Engine
This is a companion paper to 'Design and experiments of a continuous rotating detonation engine: a spinning wave generator and modulated fuel/ oxidizer mixing' submitted separately to this conference, which, called Part 1 here, focuses on the design and experiments of the CRDE engine at the University of Washington. A narrow objective of this Part 2 is to develop theories, based on the first principles, first order model, for the interpretation of the experimental data of Part 1. But our broader intent is more than that and to extend the conceptual framework wide enough to ferret out the general advantages of the CRDE for air breathing propulsion and to pinpoint the future research directions. Specifically, we discuss four phenomenologically unique topics: (1) zero total angular momentum in the lab coordinates and its implications, (2) thrust generation by pressure waves trailing detonation waves, (3) interdependence between the mass flow rate, wave number and axial size of the detonation zone, and (4) supersonic expansion in a constant area CRDE without a throat. Whenever appropriate, we compare them with related fields: spinning and multi cellular detonations and gas turbines.