Laser Doppler Velocimetry is a non-invasive optical measurement technique used to determine the velocity of moving particles, typically in fluid flow systems. It relies on the Doppler effect, which occurs when light waves are scattered by moving particles, causing a frequency shift in the scattered light. This shift is directly proportional to the velocity of the particles.
In Laser Doppler Velocimetry, a laser beam is divided into two beams: the reference beam and the measurement beam. The measurement beam is focused on the region of interest where the particles are present. When the particles scatter the laser light, a fraction of the scattered light is collected and interfered with the reference beam to create an interference pattern. The interference pattern is then detected by a photodetector, which measures the frequency shift caused by the moving particles.
By analyzing the frequency shift, Laser Doppler Velocimetry can accurately determine the velocity of particles within the measured volume. This technique is particularly useful in studying fluid dynamics, such as in turbulent flows, boundary layer analysis, and assessing velocity profiles in various industrial applications.
Laser Doppler Velocimetry offers several advantages over traditional measurement methods, including its non-invasive nature, high spatial and temporal resolution, and the ability to measure velocity in inaccessible or hazardous environments. It is widely used in research, engineering, and biomedical applications to study flow behavior, optimize system performance, and understand various physiological processes within the human body.
