FLUORESCENCE IMAGING OF OH AND NO IN A MODEL SUPERSONIC COMBUSTOR

Recent results are presented from an experimental study to develop Planar Laser-Induced Fluorescence (PLIF) diagnostics for application to scramjet combustor development. The measurements are made in a reacting now shock-tunnel facility which generates Mach 3 air at static conditions of 1500 K and 0.3 atm. Hydrogen or other gases may be injected into the rectangular test section downstream of a rear-facing step. PLIF measurements of NO, naturally present in the reflected shock-heated, freestream air, are used to determine basic flow features, and a technique is demonstrated for determining static temperature variations in nonreacting, non-mixing portions of the now. PLIF measurements of OH are used to reveal the instantaneous reaction zone interface from a dual round jet injector configuration. Issues associated with quantitative PLIF data interpretation in compressible reacting flows are discussed in detail.