Understanding Wind Noise
Aeroacoustic (airflow-induced) noise is a difficult topic, and its theory is still under development.
Understanding aeroacoustic noise requires accounting for the physics of both unsteady flow and sound waves simultaneously. Although no complete scientific theory of the generation of noise by aerodynamic flows has been established, most practical analysis relies on the so-called 'aeroacoustic analogy'*, proposed by Sir James Lighthill.
Measuring aeroacoustic noise with both external and in-canal microphones.
Measuring targeted wind flow noise at different head / ear locations and velocities.
Measuring turbulent pressure fluctuations and correlating to in ear wind noise measurements.
Smoke flow visualization / laser light imagery and fluorescein dye visualization / laser light imagery
Constructive testing and analysis. Adding and subtracting different parts of the ear using modeling clay.
Hot wire and static / dynamic pressure probe anemometers. Measuring and mapping flow / velocity patterns.
* "Lighthill's theory of aerodynamic noise consists in drawing an analogy between the full nonlinear flow problem and the linear theory of classical acoustics." - Principles of Aerodynamic Noise Generation, D. G. Crighton, Department of Applied Mathematical Studies, University of Leeds, Leeds, England (1975)
Understanding wind noise helps us develop the most effective products.