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
Stretchable biofuel cells extract energy from sweat to power wearable devices
22.08.2017 | University of California - San Diego
Laser sensor LAH-G1 - optical distance sensors with measurement value display
15.08.2017 | WayCon Positionsmesstechnik GmbH
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Health and Medicine
22.08.2017 | Materials Sciences
22.08.2017 | Life Sciences