AFRL-OSR-VA-TR-2015-0187 Premixed Supersonic Combustion

Hypersonic air-breathing engines rely on scramjet combustion processes, which involvehigh speed, compressible, and highly turbulent flows. The combustion environment andthe turbulent flames at the heart of these engines are difficult to simulate and study in thelaboratory under well controlled conditions. Typically, wind-tunnel testing is performedthat more closely approximates engine testing rather than a careful investigation of theunderlying physics that drives the combustion process. The experiments described in thisreport, along with companion data sets developed separately, aim to isolate the chemicalkinetic effects from the fuel-air mixing process in a dual-mode scramjet combustionenvironment. A unique fuel injection approach is taken that produces a uniform fuel-airmixture at the entrance to the combustor. This approach relies on the precombustionshock train upstream of the dual-mode scramjet combustor. A stable ethylene flameanchored on a cavity flame holder with a uniformly mixed combustor inflow was achievedin these experiments, allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laserinduced fluorescence (PLIF) to be performed.DISTRIBUTION A: Distribution approved for public release. Distribution StatementThis is block 12 on the SF298 form. Distribution A Approved for Public Release Explanation for Distribution StatementIf this is not approved for public release, please provide a short explanation. E.g., contains proprietaryinformation. SF298 FormPlease attach your SF298 form. A blank SF298 can be found here. Please do not password protect or securethe PDF The maximum file size for an SF298 is 50MB. AFD-070820-035 Goyne Ver 2.pdf Upload the Report Document. File must be a PDF. Please do not password protect or secure thePDF . The maximum file size for the Report Document is 50MB. Premixed Supersonic Combustion Final Report Ver 2.pdf Upload a Report Document, if any. The maximum file size for the Report Document is 50MB.Archival Publications (published) during reporting period:Changes in research objectives (if any):Change in AFOSR Program Manager, if any:Extensions granted or milestones slipped, if any: Added Sections II, V(1) and VII to report AFOSR LRIR NumberLRIR TitleReporting PeriodLaboratory Task ManagerProgram OfficerResearch ObjectivesTechnical SummaryFunding Summary by Cost Category (by FY, $K) Starting FY FY+1 FY+2