Quantitative 2D thermometry in turbulent sooting non-premixed flames using filtered Rayleigh scattering.

This paper demonstrates the application of a thermometry method in turbulent sooting non-premixed flames using filtered Rayleigh scattering (FRS). Fuel tailoring is used to establish a specific C2H2-based fuel mixture such that temperature can be determined accurately by a single FRS measurement over the entirety of mixture fraction space, or equivalently, for all relevant thermo-chemical states. Evaluation is performed in a hierarchy of flows to establish measurement precision and accuracy. Initial assessments in a series of heated fuel mixtures; non-sooting, near-adiabatic flat flames; and laminar non-premixed sooting flames show accuracy of the approach over a full range of expected temperatures and high single-shot measurement precision (e.g., 65

Evaluation of the Tenti S6 model for hydrocarbon fuels at elevated temperatures using filtered Rayleigh scattering measurements.

This Letter targets the assessment of the well-known Tenti S6 model for predicting the Rayleigh-Brillouin scattering (RBS) spectra of select gas-phase hydrocarbon fuels (CH4, C2H2, C2H4, C3H8, and C4H10) over a temperature range of 300 to 700 K. The Tenti S6 model is evaluated by comparing filtered Rayleigh scattering (FRS) measurements to synthetic FRS signals generated from the combination of the Tenti S6 output and an accurate iodine absorption filter model. The experimental and synthetic FRS results agree very well (<3% difference) over the full temperature range for CH4, C2H2, and C2H4, indicating accurate calculation of the RBS spectra. For C3H8 and C4H10, there are some large differences between the experimental and synthetic FRS results which cannot be resolved through tuning of bulk viscosity, internal heat capacity, or inclusion of vibrational degrees of freedom, suggesting the need for detailed measurements of the Rayleigh-Brillouin spectra.