For a normal test of a prototype rotor blade, the simultaneously occuring loads in the field are simplified. As part of the “Future rotor blade concept” research project, scientists at Fraunhofer IWES are developing new methods that provide significantly more realistic data and allow a load-appropriate design to be produced. The Federal Ministry for Economic Affairs and Energy and the Federal State of Bremen intend to invest € 10 million to further develop methodological expertise and an innovative test infrastructure in Bremerhaven.
Reliable and economical determination of the operational robustness of XXL blades
Better safe than sorry: Since, in reality, only one rotor blade will undergo the complete blade testing procedure right through to certification, the calculative safety factors selected are not necessarily those leading to optimum costs, but rather those which can cope with the operational loads with certainty. A higher number of tests that can be realized at reasonable cost allow the safety margins to be reduced, which, in turn, means a more economical design for the rotor blades.
This is the starting point for the rotor blade experts at Fraunhofer IWES. Separating a blade into segments for testing - e.g. root segment and rotor blade tip - has two advantages: Tests become possible at higher frequencies and with a more accurate load profile. The tests are rendered even more accurate when individual sections with a critically high load and greater material thickness or strong curvatures, for example, are investigated separately. This innovative approach not only produces more informative results, but also reduces the testing times by a calculated 30%, which means a noticeable cost saving.
Test infrastructure to be operational by the middle of 2018
At the conclusion of the first phase of the research project, which will take five years in total, the infrastructure will be operational and the test methods developed. Florian Sayer, head of department, commented on the time frame as follows: “It is a very ambitious schedule, but we can build on ten years of experience with mechanical test methods and a sound understanding of material properties and the behaviour of fibre composites; and the pressure in the industry to innovate is a definite incentive.”
Rotor blade for detailed investigations
While component and blade segment tests are already turning up more and more frequently in the industry’s list of requirements, the testing of critical sections is still a long way off. This is done by dividing the rotor blade according to the requirements of the investigation in order to be able to take a closer look at the critical areas. The subsequent execution of the load tests requires a complex infrastructure and profound knowledge of how complex load cases affect the structure.
A so-called hexapod test stand with a Reynolds platform to apply torsion forces and bending moments in parallel is being constructed in Bremerhaven - right next to the established complete-blade test stands and material testing laboratories. Manufacturers of rotor blades benefit from significantly shorter tests and particularly realistic load simulations, and their modified infrastructure set-up leads to lower energy costs as well.
From the overall perspective of the wind power industry, these test facilities play their part in reducing the energy production costs: When developers have a sure foundation on which they can employ greater creative freedom to develop a blade design optimised for efficiency and reliability, the economic efficiency of wind power utilization and thus its development potential increases.
Britta Rollert | Fraunhofer Institut für Windenergie und Energiesystemtechnik IWES
Factory networks energy, buildings and production
12.07.2018 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
Manipulating single atoms with an electron beam
10.07.2018 | University of Vienna
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences