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Updated: Jul 2, 2026
10:53
Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques
Published on: March 12, 2019
Instantaneous laser Doppler velocimeter using a fast wavelength tracking Michelson interferometer.
The Review of Scientific Instruments
|November 1, 1978
Summary
A novel laser Doppler velocimeter uses wavelength detection and a two-beam interferometer for precise velocity measurements. This system achieves microsecond time resolution for applications in gas flows and moving surfaces.
Area of Science:
- Optical Physics
- Metrology
- Instrumentation Engineering
Background:
- Laser Doppler velocimetry (LDV) is crucial for fluid dynamics and surface analysis.
- Existing LDV systems face limitations in time resolution and sensitivity to environmental factors.
Purpose of the Study:
- To introduce a new laser Doppler velocimeter (LDV) system utilizing wavelength detection.
- To enhance the precision and time resolution of velocity measurements.
Main Methods:
- A two-beam interferometer with a finite optical path difference (Deltaphi) was employed.
- A fast feedback system maintained constant phase (Deltaphi/lambda).
- A Pockels cell modulated the optical path difference in response to wavelength shifts.
Main Results:
- The system demonstrated sensitivity to wavelength changes, enabling velocity detection.
- Continuous velocity signals were generated via Pockels cell voltage.
- Achieved a time resolution of 1 microsecond or lower.
Conclusions:
- The developed LDV system offers high-speed, accurate velocity measurements.
- Potential applications include gas flow analysis with tracer particles and moving surface velocity monitoring.
- Experimental validation confirmed the system's performance capabilities.
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