As blade specialists, we know what it takes to boost performance, while minimizing loads on the turbine and reducing costs:
- Hybrid carbon design and manufacturing, enabling us to create the world’s longest and most advanced blade – the LM 107.0 P.
- In-house aerodynamic experts, combined with innovative software, not only ensure tailored blade designs – our engineers also develop customized add-on’s to optimize blade performance and reduce noise
- And ultimately, engineers verify the designs in our unique, onsite research facilities – including a rain erosion laboratory, full-scale test center and wind tunnel
Below, explore the design, materials and testing that back up our phrase, "We know blades."
Everything we do is by design.
LM Wind Power has perfected the art of blade design over the past three decades. While the digital age has changed the way we generate our designs, the balance between key properties and fundamental blade concepts continue to form the basis of our designs.
The optimal balance between price and performance.
Via smart engineering, we 'stretch' what our materials are capable of and continually expand the envelope of what can be achieved.
Performance and reliability through rigorous testing.
We are the only wind turbine blade manufacturer to have our very own wind tunnel and in-house testing facilities for full scale blade tests.
The art of blade design
Our fundamental blade constant has not changed since we first began producing blades in 1978: two glass fiber shells attached to rigid webs. For our new generation of blades, finding the perfect balance between aerodynamics and structure presents the greatest design challenge for each blade type.
Reliability down to the tiniest detail
Knowing and understanding materials and how they interact is crucial for finding the perfect balance between performance, reliability and cost.
We base our blade material technology on stable, well-tested materials, providing the best possible balance between price and performance. Via smart engineering, we ”stretch” what the materials are capable of and continually expand the envelope of what can be achieved.
We successfully apply composite resins to our products, while respecting the required mechanical properties for high performing wind turbine blades and safe working conditions. We also map the properties of the different applied materials and understand how the different elements in our composite material work together and how blades perform under real life conditions.
Known for their reliability, the material technology in our blades holds up against degradation by chemicals and water. With a proven track record of more than 228,000 blades installed since 1978, we know our blades will perform under varying conditions of wind, temperature and humidity. We deliberately pull blades to their breaking point to measure how and when they break, and we continuously improve our products with the latest material innovations.
Strength and endurance
Rigorous testing to ensure reliability throughout the wind turbine blade's lifetime.
Keeping all the test facilities in-house gives us the highest level of flexibility and helps us deliver the blades to our customers sooner. We currently have four test beds for dynamic testing and one for static testing. The largest of these has recently been extended, with a capacity to test blades as long as 80 meters. Besidesstatic and dynamic tests, new blade types are also tested atour very own wind tunnel. This sophisticated tunnel allows our team of scientists and engineers to test the aerodynamic properties of our blade types in simulated conditions that match real wind conditions.
Our testing laboratory has been accredited for the testing of wind turbine blades by DANAK – the Danish Accreditation and Metrology Fund under ILAC (the International Laboratory Accreditation Cooperation). This means that our measurements and reports can be used as the basis for blade type approval by authorities such as Det Norske Veritas (DNV) in Norway and Germanischer Lloyd (GL) in Germany.
As part of the accreditation process, LM Wind Power’s technical expertise and processes were studied using the ISO 9001 and DS/EN ISO/IEC 17025 standards concerning general requirements for testing and calibration laboratories. In addition, DANAK carries out annual audits in our laboratory.
Pure wind at 105 meters per second
Our engineers and scientists use our custom made wind tunnel to optimize the aerodynamic benefits of our blades. Tests of airfoils in the wind tunnel helps in understanding the complexity of flow physics and allows the continuous development of numerical approaches.
The tunnel dimensions are 1.35 m width, 2.70 m height and 7.00 m length. This gives very little blockage and only limited streamline curvature for an airfoil model with a 900 mm chord. A maximum wind speed of 105 m/s can be generated in the wind tunnel and a cooling system in the tunnel is used to remove the excess heat at high wind speeds.
The test setup for the airfoil model involves a high-accuracy turn table device for holding the airfoil model, as well as an automatic traverse system holding a wake rake. In total almost 300 sensors are used to characterize the airfoil flow including differential pressure sensors and a load cell system. An automatic data acquisition system allows a high level of uniformity between different tests. To qualify flow patterns with flow visualization techniques, we apply established methods utilizing infrared camera, tufts, smoke and oil.
One of the upcoming challenges at our wind tunnel is to conduct high precision experiments to measure the sound level generated by an airfoil. This means new skills, measurement technologies and a tuning of the current wind tunnel to a low sound level aero-acoustic laboratory.
Ready for anything
We subject every new blade type to extreme loads and fatigue tests to ensure reliability throughout its lifetime, and lighting tests to ensure the lightning protection on the blades can withstand powerful storms.
All new blade types undergo static testing before they are approved. A traction rig is attached to the blade by steel wires fixed at select points and then the blade is pulled to a point where it is subjected to the prescribed maximum load. The extreme load is tested on all sides for a week - leading edge, trailing edge, suction side and pressure side to ensure that it does not break. The whole program is repeated after dynamic testing to ensure that the blade can handle extreme loads even after high fatigue.
Dynamic testing takes considerably longer. The aim is to subject the blade to fatigue loads corresponding to 20 years of normal wear and tear. This is done by setting the blade into five million oscillations edge wise and flap wise. During the test, an infrared camera is used to check for small breaks or cracks in the laminate.
When new materials are used or other significant changes are made to the blade type, a crash test may be added to the static and dynamic tests. In a crash test, a static test is continued until the blade breaks. The blade is then cut open at the point of fracture, and the surfaces, etc. are investigated in detail to discover the root cause.
We know blades
Here's what it takes to build the most advanced, reliable and high-quality wind turbine blades in the industry.