The BeRT: Berlin Research Wind Turbine

SMART BLADE designed and developed the first Smart-Wind Turbine for the researchers of the Institute of Fluid Dynamics and Technical Acoustics of TU Berlin. The general specifications were based on the research needs and a design proposal was drafted by the R&D team of SMART BLADE.  The design proposal of SMART BLADE GmbH was promoted and the complete turbine was successfully developed, designed and manufactured. The official name of the research turbine is BeRT, which stands for Berlin Research Turbine. 

SMART BLADE currently offers both copies of the Berlin Research Turbines (BeRT)  or custom designs of research wind turbines according to individual specifications.  

 

CAD view of the research wind turbine design

Some more details about the BeRT

The BeRT turbine design evolves around four main design pillars: 

> Integration of sensors, data acquisition and control in the rotating system

> Flexible operation with respect to speed and torque

> Modular construction

> Ultimate safety

 

The basic turbine specifications are:

> Three bladed rotor with a diameter of 3m

> 2.1m tower height (designed for 4.2 x 4.2m wind tunnel section)

> Design tip speed ratio (TSR) is 4.6 (180rpm rated speed at 6m/s inflow wind v velocity)

> Speed range of 100 to 250rpm 

 

The turbine is located inside the settling chamber of the Large Wind Tunnel facility of HFI TU Berlin. The non-ideal inflow conditions at this section of the wind tunnel are actually an advantage of this setup since it is now possible to test the turbine in a more realistic environment, which includes wind shear and turbulence.

The turbine is designed as a stiff system, with the compliance and deflections of its main components kept to an absolute minimum. This ensures that pure aerodynamic flow solvers are able to accurately represent the performance of this machine without the influence of major aeroelastic and structural effects. 

 

Cut-view of the hub and nacelle of the BeRT

The SMART BLADES of BeRT

BeRT is the first wind turbine in Germany to be equipped with smart blades! No other company has more experience in smart wind turbine rotorblades than SMART BLADE. Bellow are a few information about the blade design and its active flow control devices. 

The blade comprises a single airfoil cross-section, which is based on a slightly modified version of the Clark-Y airfoil. The use of that airfoil was dictated by strict aerodynamic simulation requirements (i.e. the blades have to cope well with CFD simulations). 

The modified airfoil was smoothed, based on an iterative smoothing algorithm developed by SMART BLADE. The outcome is a near-perfect airfoil contour and therefore also a perfect CAD surface of the blade. This in turn leads to a smooth and accurate mold which requires almost no additional manual sanding processes after its machining. The rotorblade planform is designed with focus on aerodynamics. It incorporates a  linear twist and chord distribution in the area where leading and trailing edge devices are to be implemented (e.g. rigid or flexible flaps). The design tip speed ratio (TSR) is 4.6 and requiring a maximum chord of more than 400mm  in combination with a twist of more than 20° in order to achieve near optimal shape. 

The airfoil smoothing process, which allowed the creation of a very smooth and accurate blade mold
The twist and chord distribution of the BeRT rotorblades
The first operational Smart Blade in Germany!

Assembly & Operation

The entire wind turbine was designed for repetitive assembly and disassembly in the wind tunnel. The main sub-assemblies of the machine can be removed and put back together without major difficulties, using simple tools. Accessibility has been kept to the highest possible level in order to allow for system access without part removals. Special pitch angle tuning plates with engraved pitch angle settings have also been provided in order to assist the easy and fast blade pitch setting. Operation and control are performed from a control unit outside the wind tunnel. The control cabinet is an integrated unit with the entire electronics and control hardware. The turbine can be operated in either manual or computer controllable mode (i.e. torque/rpm control). The maintenance requirements of the turbine have been kept to an absolute minimum, making it a very effective experimental device.  

View of the Berlin Research Turbine in front of the large Wind Tunnel Facilities of HFI TU Berlin

More Information

For more information on the BeRT, as well as for pricing information on this research turbines or quote request for custom developments please send us an e-mail at: info[at]smart-blade.com