Dual holographic interferometry for measuring the three velocity components in a fluid plane

Area of Science:

• Fluid dynamics
• Optical measurement techniques
• Holography

Background:

• Measuring fluid velocity components is crucial for understanding fluid dynamics.
• Traditional methods may require multiple recordings or complex setups.
• Simultaneous measurement of all three velocity components presents a significant challenge.

Purpose of the Study:

• To present a novel technique for simultaneous measurement of three velocity components in a fluid plane.
• To utilize a single holographic recording with dual reconstruction processes.
• To enhance quantitative analysis in fluid dynamics research.

Main Methods:

• Developed dual holographic interferometry, combining two reconstruction processes from one holographic recording.
• Used far-field fringe patterns with an expanded laser beam for in-plane velocity components.
• Employed image-field fringe patterns with a pointwise laser beam for out-of-plane velocity components.
• Proposed two methods to combine the differently sensitive reconstruction processes.

Main Results:

• Successfully measured all three velocity components simultaneously.
• Demonstrated the technique's applicability in a fluidlike solid object.
• Validated the system's performance in a convective flow scenario.

Conclusions:

• Dual holographic interferometry offers a powerful, single-recording approach for comprehensive fluid velocity measurement.
• The technique provides quantitative data for both in-plane and out-of-plane velocity components.
• This method advances fluid dynamics analysis by simplifying data acquisition.