Investigation of methane-fueled rotating detonation combustor exhaust flow field via time-resolved particle image velocimetry

Rotating detonation combustors (RDCs) as a form of pressure gain combustion (PGC) have received increased research attention in the power generation and aerospace/defense propulsion fields due to the potentially substantial thermal efficiency advantages associated with its operation cycles as compared to traditional constant pressure combustion systems. However, significant scientific exploration must still be conducted to maximize the potential benefits of RDCs, including the implementation of proper flow conditioning devices downstream of the combustor to reduce losses associated with the inherently unsteady, shock-laden flow field. This is particularly true in power generation applications, wherein existing gas turbines prefer homogenous inlet flow conditions. Presently, there is a lack of experimental data to provide quantified measurements of the flow field emanating from RDCs. Application and analysis of diagnostics capable of accurately resolving the high-speed, high-enthalpy, and unsteady flow field has innate challenges. However, the insights provided by such measurements are necessary for further development of the technology, and when validating/refining numerical models. In this dissertation, time-resolved particle image velocimetry (TR PIV) is applied to further the understanding of the exhaust flow field of RDCs operated with gaseous methane fuel and in multiple geometric configurations and inlet condition. To the best knowledge of the author, this represents the first successful application of the TR-PIV diagnostic technique to evaluate RDC exhaust flow fields. Through the parametric variation of RDC operation conducted in this dissertation, the influence of combustor-exit area constriction and flow conditioning geometries on the resulting exhaust flow field were assessed. Three geometric configurations of the RDC were evaluated using two different PIV interrogation plane locations allowing for the discretization of the complex exhaust flow into axial, circumferential and radial components. It was found that the exhaust flow field was unsteady in every configuration tested. However, the unsteadiness was significantly reduced by constricting the exit flow area, and implementation of a diffuser geometry further attenuated the flow modulations and resulted in a much more uniform, axially oriented flow. This dissertation is therefore a summary of the diagnostic methodology implemented and results acquired from the application of TR-PIV to RDC exhaust flow fields.

Grantor dc:publisher

University of Alabama Libraries

Year dc:date.issued

2019

Author dc:creator

• Depperschmidt, Daniel

Advisor dc:contributor.advisor

• Agrawal, Ajay K.

Contributors dc:contributor

• Bittle, Joshua A.
• Hubner, James P.
• Puzinauskas, Paulius V.
• Uddi, Mruthunjaya

• Mechanical engineering
• Aerospace engineering

Statement dc:rights

• All rights reserved by the author unless otherwise indicated.

Language dc:language.iso

en_US, English

Dc Identifier Other

u0015_0000001_0003532
Depperschmidt_alatus_0004D_14047

OAI identifier oai:identifier

oai:ir.ua.edu:123456789/6674