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Asynchronous optical sampling: a new combustion diagnostic for potential use in turbulent, high-pressure flames
Optics Letters
|September 15, 2009
Summary
Asynchronous optical sampling (ASOPS) enables rapid species density measurements in turbulent flames. This pump-probe technique is viable even in highly quenched flame environments, as shown by sodium decay measurements.
Area of Science:
- Spectroscopy
- Laser Physics
- Combustion Science
Background:
- Turbulent, high-pressure flames present challenges for traditional diagnostic methods.
- Pump-probe spectroscopy offers potential for rapid measurements in dynamic environments.
Purpose of the Study:
- To demonstrate the efficacy of Asynchronous Optical Sampling (ASOPS) for species number density measurements in turbulent flames.
- To optimize ASOPS instrumental timing parameters for challenging flame conditions.
Main Methods:
- Utilizing a pump-probe technique with ASOPS.
- Maintaining a constant beat frequency between mode-locked pump and probe lasers.
- Measuring the nanosecond decay of electronically excited sodium in an atmospheric flame.
Main Results:
- Achieved rapid measurement of species number density.
- Demonstrated the viability of ASOPS in highly quenched flame environments.
- Identified and considered optimization of instrumental timing parameters.
Conclusions:
- ASOPS is a powerful technique for in-situ species measurements in turbulent, high-pressure flames.
- The method is robust and effective even under conditions causing rapid quenching.
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