The Vectoflow calibration wind tunnel
In our own calibration wind tunnel we calibrate Vectoflow probes to reach a high accuracy of measurement.
A professional calibration of a probe is essential for reliable measurement results. Calibration means defining the relationship between the concerning pressure and the measured velocity and angle of a flow. For this purpose, the probe is held in a known flow field generated by our calibration wind tunnel. We measure the pressure for various points of measurement by changing the angle of attack of the flow in the air flow. With these results we calculate the calibration factors for the probe. When the probe later recognizes an unknown flow field, it implies the unidentified velocity of this flow by using the measured pressure and the earlier defined calibration factors.
As a basis of every calibration serves a good free jet – a constant, homogenous air flow with low turbulence. A 90kW asynchronous motor propels 2 centrifugal compressors over a belt drive. Afterwards the compressed air is guided in a setting chamber through multiple sieves and honeycomb rectifiers to reach a homogenous air flow. Then various nozzles with a special geometry for low pressure loss, speed up the compressed air. We are able to reach velocities between 1 m/s and Mach 1.4. The probes are positioned by a 2-axis traverse (roll- and yaw angle) at a total accuracy of 0.05°, to realise an exact calibration for the custom defined field of velocity and angle.
Performance parameters of the calibration wind tunnel
|Angle range||±165° (yaw), ±180° (roll)|
|Maximum power||90 kW|
|Velocity range||1 m/s up to Mach 1,4|
|Control Types||Mach No., Airspeed (m/s), Reynolds Number|
|Temporal speed non-uniformity||±0,25% (at Ma 0,1)|