Turbulentsimõõturid

Turbulentsimõõturid are instruments used to quantify the degree of turbulence in a fluid flow. Turbulence is characterized by chaotic, irregular, and seemingly random fluctuations in velocity, pressure, and other flow properties. Measuring these fluctuations is crucial in various fields, including aerodynamics, hydrodynamics, meteorology, and process engineering.

Various types of turbulentsimõõturid exist, each employing different physical principles. Hot-wire anemometers are commonly used in air and other gases. They consist of a thin, electrically heated wire placed in the flow. The cooling effect of the fluid on the wire is measured, and this cooling rate is directly related to the flow velocity. Changes in velocity due to turbulence cause fluctuations in the wire's temperature and thus its electrical resistance, which can be detected and analyzed.

Laser Doppler velocimeters (LDVs) and particle image velocimetry (PIV) are optical methods that use lasers to measure velocity. LDVs track the Doppler shift of laser light scattered by small particles moving with the flow. PIV, on the other hand, measures the displacement of particles over a short time interval between two illuminated images of the flow field. These techniques are non-intrusive and can provide detailed velocity field information.

In liquid flows, particularly in engineering applications, devices like pitot tubes can provide an indication of turbulence levels by measuring dynamic pressure variations, though they are not as sensitive to fine-scale turbulence as other methods. Electromagnetic flowmeters can also indirectly infer turbulence from fluctuations in induced voltage. The choice of turbulentsimõõtur depends on factors such as the fluid type, flow speed, required accuracy, and whether the measurement needs to be intrusive or non-intrusive.