A laser Doppler anemometer is a device used to measure?

Fluid Mechanics | Instrumentation

⭕ (a) the turbulent velocity fluctuations in a flow

⭕ (b) shear stress at a boundary

⭕ (c) drag force on an aerofoil

⭕ (d) surface tension of a fluid

⭕ (e) wind direction

Explanation: A Laser Doppler Anemometer (LDA) is a non-intrusive optical device used to measure the velocity of fluid particles, especially in turbulent flows. Key points:

• Measures velocity based on Doppler shift of laser light scattered by particles in flow.
• Does not disturb the flow while measuring.
• Highly accurate and suitable for capturing rapid velocity fluctuations.

Laser Doppler Anemometer: What It Measures

A Laser Doppler Anemometer is an advanced instrument in fluid mechanics that uses laser optics to measure particle velocities in a flowing medium. This helps analyze turbulence without disturbing the flow.

Applications of Laser Doppler Anemometer:

• Wind tunnel studies
• Biomedical fluid dynamics
• Combustion research
• Turbulence measurement in pipelines

Conclusion:

The correct answer is (a) the turbulent velocity fluctuations in a flow. LDAs are widely used in research for their precision and non-invasive properties.