Investigation of Geometric RDC Dependencies Using a Fast Reactive Euler Solver

Abstract

A time resolved, two-dimensional reactive Euler solver is employed to simulate Rotating Detonation Combustion (RDC). The influence of combustor diameter, axial length, combustion annulus mass flux, outlet throat area, and air injector area on the flow field geometry and performance is studied. There is a similarity in the unsteady outlet state for cases at equal combustor aspect ratio. It is demonstrated that generalization of Equivalent Available Pressure methodology for the non-constant heat capacity ratio case is not trivial and can introduce significant errors. To bypass this issue, an alternative approach for performance quantification is introduced. Mass flux and outlet throat area are found to have a significantly stronger effect on performance compared to diameter and axial length. Yet, the influence of the latter two is significant. The angle of the oblique shock is quantified and is shown to correlate with the ratio of detonation height and axial combustor length. The results suggest that entropy generation due to shock processing is the driving mechanism behind performance deviation due to changes in combustor diameter and axial length. Approximate predictions about the shock processing can be made using geometric dependencies of the flow field.