Distributed Airflow Sensing Based on High-Spatial-Resolution BOTDA and a Self-Heated High-Attenuation Fiber

Area of Science:

• Fiber optic sensing
• Optical physics
• Distributed sensing technologies

Background:

• Accurate airflow measurement is crucial in various industrial and environmental applications.
• Existing distributed sensing methods face challenges in spatial resolution and sensitivity to airflow.

Purpose of the Study:

• To propose and demonstrate an all-fiber distributed airflow sensing method.
• To achieve high spatial resolution and accuracy in airflow detection and characterization.

Main Methods:

• Utilizing a self-heated high-attenuation fiber (HAF) to create a temperature gradient in the sensing fiber.
• Employing differential pulse-width pair Brillouin optical time domain analysis (DPP-BOTDA) to measure the temperature distribution.
• Detecting airflow by analyzing heat loss, reflected as changes in Brillouin frequency shift.

Main Results:

• Achieved a spatial resolution of 5 cm for temperature distribution measurement.
• Demonstrated accurate detection of airflow movement, multiple airflow sources, and airflow deflection angles.
• Positioning error for airflow was less than ~2.2 cm, with a maximum angle demodulation error of 2.5° within 0-30°.

Conclusions:

• The proposed DPP-BOTDA and HAF-based system offers a viable solution for distributed airflow sensing.
• The method provides high spatial resolution and accuracy for complex airflow measurements.
• This technology has potential applications in environmental monitoring, industrial process control, and safety systems.