The five-hole probe anemometer in the probe anemometer is a precision airflow measurement instrument, which is mainly used to obtain airflow velocity distribution information at specific points in three-dimensional space. Its operating principle is based on the principles of pressure measurement and fluid mechanics, as follows:
The role of the probe anemometer1Structural features:
Five small holes are evenly distributed on the five-hole probe, which can include three radial holes (for measuring the radial velocity component) and two axial holes (for measuring the axial velocity component), and the velocity component of the airflow in each direction is determined by measuring the pressure difference at each hole.
2.Pressure-velocity relationship:
According to Bernoulli's theorem, in the flow of an incompressible fluid, where the flow velocity increases, the static pressure decreases. The probe is connected with a pressure sensor inside, and when the air flow passes through the small holes at different locations, different relative static pressures will be formed at the orifices. By measuring the static pressure values at each hole, combined with the continuity equation and the law of conservation of momentum, the flow velocity components in each direction can be calculated.
Winterner miniature five-hole probe anemometer.
3.Data Processing:
By analyzing the pressure signal measured by each hole, the three-dimensional velocity vector of the flow field can be solved by using a preset mathematical model or software algorithm. This method allows researchers to obtain a more accurate and detailed velocity distribution of the flow field, allowing for in-depth study of complex flow phenomena.
4.Practical Applications:
Five-hole probe anemometers are widely used in experimental hydrodynamic testing in aviation, aerospace, automotive, energy and other fields, especially in wind tunnel experiments, to accurately determine aerodynamic properties, such as eddy currents, boundary layers and turbulence characteristics. Because of its ability to provide velocity component data in multiple directions, it is particularly important for studies that require detailed details of complex flow fields.
Editor: Wu Jiahui.