Composition-partitioned volumetric dynamic temperature imaging.

Area of Science:

• Optical Engineering
• Combustion Science
• Imaging Technology

Background:

• Accurate 3-D imaging of dynamic combustion fields is crucial for understanding complex phenomena.
• Conventional methods face limitations in speed, accuracy, and handling non-uniform compositions.

Purpose of the Study:

• To develop a real-time holographic tomography technique for high-speed, quantitative 3-D combustion imaging.
• To improve the accuracy of temperature reconstruction in dynamic and stratified combustion environments.

Main Methods:

• A three-angle Mach-Zehnder interferometer with off-axis multiplexed recording for simultaneous multi-path acquisition.
• Simultaneous multi-path acquisition within a single shot.
• Application of ART+TV regularization to mitigate angular sparsity and enhance imaging fidelity.
• Introduction of a composition-partitioned model for accurate temperature reconstruction, overcoming the fixed-air assumption.

Main Results:

• Achieved 3-D temperature imaging of propane flames at 6x10^3 fps.
• Demonstrated relative deviations within 1.14-1.93% compared to thermocouple measurements.
• Successfully reconstructed temperatures up to 1750 K in dynamic combustion fields.

Conclusions:

• The presented holographic tomography technique offers a powerful tool for real-time, quantitative 3-D analysis of transient combustion and dynamic flow fields.
• The improved temperature reconstruction model enhances accuracy in complex combustion scenarios.
• This technique has significant potential for rapid diagnosis and research in combustion science.