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Slow-flow measurements and fluid dynamics analysis using the Fresnel drag effect
Applied Optics
|October 12, 2010
Summary
A Sagnac interferometer measures optical phase shifts from the Fresnel drag effect in moving water. This system accurately detects low flow rates and measures velocity profiles and turbulence.
Area of Science:
- Optics
- Fluid Dynamics
- Metrology
Background:
- The Fresnel drag effect describes how light is affected by the motion of a medium.
- Accurate measurement of fluid flow is crucial in various scientific and industrial applications.
- Traditional flow meters can introduce significant pressure drops.
Purpose of the Study:
- To develop and demonstrate a Sagnac interferometer system for measuring optical phase shifts induced by the Fresnel drag effect.
- To utilize this system for precise detection of low volumetric flow rates in water.
- To investigate the system's capability in measuring water velocity profiles and turbulence.
Main Methods:
- A Sagnac interferometer was employed to detect optical phase shifts.
- The system was calibrated and tested using flowing water.
- Volumetric flow rates, pressure drop, velocity profiles, and turbulence were measured.
Main Results:
- The Sagnac interferometer successfully measured optical phase shifts due to the Fresnel drag effect.
- The system demonstrated the ability to detect volumetric flow rates as low as 43 µL/min.
- A minimal pressure drop was maintained across the measuring pipe.
- Velocity profiles and turbulence characteristics of flowing water were successfully measured and analyzed.
Conclusions:
- The Sagnac interferometer is a viable tool for measuring optical phase shifts related to the Fresnel drag effect.
- The developed system offers high sensitivity for detecting low flow rates in fluids.
- This technique provides a non-intrusive method for characterizing fluid dynamics, including velocity profiles and turbulence, with minimal impact on the flow itself.
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