Two-point OH time-series statistics for turbulent partially premixed jet flames

Two-point time-series measurements of OH are reported in a series of turbulent partially premixed H₂/CH₄-air flames by employing two-point picosecond time-resolved laser-induced fluorescence (PITLIF). Spatial and temporal autocorrelation functions, and corresponding integral length and time scales, are computed from the time series, permitting a detailed investigation of [OH] structures within the partially premixed flames. By varying Reynolds numbers and fuel-stream equivalence ratios, we examine the effects of these parameters on the integral length and time scales. Interpretation of these results draws upon knowledge of turbulent nonpremixed jet flames and partially premixed combustion, which highlights turbulence-chemistry interactions.