General Description

SMART BLADE maintains a research cooperation with the Hermann Foettinger Institute (H.F.I) of TU Berlin (Chair of Fluid Dynamics). The Wind turbine research group of Prof. C.O. Paschereit and the engineers of SMART BLADE work closely together on many research topics. A lot of experimental investigations of the company are performed at the Large Wind Tunnel Facilities of the H.F.I., but also other tunnels from the institute are available for testing.

SMART BLADE owns several constant chord, zero twist quasi-2d wind tunnel test wings. These are designed in-house and are machined with high precision CNC milling machines out of special form building material. The chord of the test wings is 600mm and the span 1540mm. Several test wings, based on airfoils that are frequently used in wind industry, are available for individual investigations. For specific airfoil tests, we also offer our experience and capabilities of designing and deliver custom test wings.

 

View of the Large Wind Tunnel of H.F.I. at TU Berlin [Source: SMART BLADE]

Large Wind Tunnel

The test wings are mounted inside the test section on a 6-component digital force balance. The balance is completely de-coupled from the wind tunnel structure in order to avoid measurement errors caused by wind tunnel vibrations.

The test section of this wind tunnel has a cross section of 2m x 1.4m, a contraction ratio of 6.25:1 and a free stream turbulence below 0.5%. The Reynolds number during the measurements with the test wings of SMART BLADE is as high as 1.5 x 106. The wind tunnel test section is equipped with additional side walls in order to reduce the effects of the wind tunnel boundary layer to the measurements and to avoid strong cross-flows.

The lift, drag and moment coefficients are  measured with the digital balance at a sampling rate of 10kHz for 20.000 samples/AoA and the results are averaged and corrected for wake blockage and solid blockage. The measurement control and the digital data acquisition is done via a wind tunnel control software developed in-house by SMART BLADE.

Lift polar before and after the wake blockage and solid blockage correction. The polar was measured at the H.F.I wind tunnel [Source: SMART BLADE]
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    Schematic of the test section of the Large Wind Tunnel of H.F.I. TU Berlin [Source: H.F.I & R. Meyer (DLR)]
  • Schematic of the 6-component digital balance, used for the force measurements [Source: H.F.I & R. Meyer (DLR)]

For the purposes of flow analysis and flow visualization during wind tunnel measurements, a Particle Image Velocimetry (PIV) system can be used. Both a Mono and a Stereo PIV system are available and can be used with high speed cameras and image processing software in order to analyze complex 3D high speed flows. SMART BLADE uses the PIV systems mostly for research in the field of passive and active flow control (e.g. Vortex Generator development). 

View of a test wing mounted inside the wind tunnel with the laser sheet of the Mono PIV system scanning its trailing edge region [Source: SMART BLADE]

More Information

For more technical information, wind tunnel test campaign requests and pricing please
contact us at: info[at]smart-blade.com