Multispectral coded light for high-speed temperature imaging of aluminum combustion.

Area of Science:

• Combustion science
• Materials science
• Energy science

Background:

• Aluminum is a key carbon-free fuel candidate.
• Understanding aluminum combustion at the single-particle level is crucial for its application.
• Measuring transient temperatures of burning aluminum droplets is difficult due to their small size, high temperatures, and rapid dynamics.

Purpose of the Study:

• To develop a quantitative, time-resolved temperature imaging technique for aluminum droplet combustion.
• To overcome the challenges of measuring temperatures of small, fast-moving, high-temperature burning particles.
• To provide insights into the fundamental combustion dynamics of aluminum.

Main Methods:

• A multispectral pyrometry approach using a passive frequency recognition algorithm for multiple exposures (FRAME).
• Employed a single high-speed monochrome camera with spectral multiplexing for simultaneous multi-wavelength acquisition at 50 kHz.
• Applied multi-wavelength pyrometry analysis to spectrally encoded images for temperature mapping.

Main Results:

• Achieved quantitative, time-resolved temperature imaging of aluminum droplet combustion.
• Generated spatially resolved temperature maps in the range of 2000-4000 K.
• Captured ignition, droplet formation, and flame development stages with high temporal fidelity.

Conclusions:

• The demonstrated FRAME technique offers an economical and flexible pyrometry solution for harsh conditions.
• Provides valuable insights into aluminum combustion dynamics.
• Supports the advancement of aluminum as a recyclable, carbon-free fuel.