Modes of plasma-stabilized combustion in cavity-based M=2 configuration

This paper considers the modes of plasma-stabilized supersonic combustion in a cavity-based flameholding configuration. The testing was performed in the SBR-50 supersonic facility at the University of Notre Dame under the following conditions: Mach number M = 2, stagnation pressure and temperature P-0 = 1-3.2 bar, T-0 = 295-750 K, and an ethylene injection rate of (m) over dot(C2H4) = 0-8 g/s. A rail type electric discharge is employed in this work, which represents a modification of the previously explored quasi-DC (Q-DC) configuration. Two principally different cases are realized and described in detail: in- or over-the-cavity combustion, and bulk combustion characterized by a significant increase of pressure downstream of the fuel injection ports. Rail discharge performance is compared to the performance of Plasma-Injection Modules (PIMs) using a 1D analysis. Dimensionless analysis of the plasma-assisted combustor performance indicates reasonable agreement of the in-cavity combustion mode with the Ozawa stability diagram, while the plasma-assisted bulk combustion is essentially distinct from this formalism.

Automated summary

This paper investigates the modes of plasma-stabilized supersonic combustion with a cavity-based flameholding configuration, testing different combustion scenarios and comparing rail discharge performance with Plasma-Injection Modules. Dimensionless analysis shows good agreement of in-cavity combustion mode with the Ozawa stability diagram, while plasma-assisted bulk combustion differs substantially from this formalism.