Global rainbow thermometry: improvements in the data inversion algorithm and validation technique in liquid-liquid...

Area of Science:

• Fluid dynamics
• Optical measurement techniques
• Thermometry

Background:

• Accurate measurement of droplet size and temperature is crucial in multiphase flow systems.
• Existing techniques may be intrusive or lack comprehensive data acquisition.
• Global rainbow thermometry (GRT) is a nonintrusive optical method for droplet characterization.

Purpose of the Study:

• To present improvements in the validation of the nonintrusive global rainbow thermometry (GRT) technique.
• To introduce a novel data inversion algorithm for GRT that utilizes the complete rainbow pattern.
• To experimentally validate the GRT technique for determining temperature and size distributions of liquid droplets.

Main Methods:

• Development of a new data inversion algorithm for GRT.
• Experimental setup for liquid-liquid suspension.
• Application of GRT to measure mean droplet temperature and size.
• Comparison of GRT measurements with results from alternative measurement techniques.

Main Results:

• The study presents enhanced validation for the GRT technique.
• The proposed algorithm effectively processes the entire rainbow pattern for improved accuracy.
• Experimental results demonstrate GRT's capability in characterizing liquid droplets within a liquid-liquid suspension.

Conclusions:

• The validated GRT technique provides accurate measurements of droplet temperature and size distributions.
• The new inversion algorithm enhances the reliability of GRT.
• GRT is a promising nonintrusive method for droplet characterization in various bulk media.