Line Raman, Rayleigh, and laser-induced predissociation fluorescence technique for combustion with a tunable KrF...

Area of Science:

• * Combustion Science and Engineering
• * Laser-Based Spectroscopic Diagnostics
• * Turbulent Flow Analysis

Background:

• * Accurate measurement of species concentration and temperature is crucial for understanding turbulent flames.
• * Existing techniques often lack the spatial and temporal resolution required for detailed flame structure analysis.
• * Hydrocarbon flames present complex chemical kinetics and mixing processes.

Purpose of the Study:

• * To develop and validate a multi-species, temperature-measurement technique for turbulent flames.
• * To assess the capability of the technique for instantaneous, line-profiling measurements.
• * To obtain detailed local flame structure data in highly turbulent combustion.

Main Methods:

• * Application of combined UV Raman, Rayleigh, and laser-induced predissociation fluorescence.
• * Instantaneous, simultaneous line measurements (11.4 mm) of CO(2), O(2), CO, N(2), CH(4), H(2)O, OH, and H(2) concentrations and temperature.
• * Validation in laminar premixed methane, laminar hydrogen diffusion, and turbulent rich premixed methane flames.

Main Results:

• * Successful instantaneous and simultaneous measurement of multiple species and temperature along a line.
• * Acquisition of gradients with respect to mixture fraction and spatial direction.
• * Demonstrated capability in laminar and highly turbulent flame environments.

Conclusions:

• * The developed laser-based technique enables detailed, instantaneous profiling of turbulent flame structures.
• * The method provides crucial data for validating combustion models and understanding flame dynamics.
• * This technique significantly advances the diagnostic capabilities for turbulent combustion research.