University of Minnesota researchers are first to use natural snow to visualize airflow of large-scale wind turbine
A first-of-its-kind study by researchers at the University of Minnesota (UMN) using snow during a Minnesota blizzard is giving researchers new insight into the airflow around large wind turbines. This research is essential to improving wind energy efficiency, especially in wind farms where airflows from many large wind turbines interact with each other.
The study by researchers at the UMN College of Science and Engineering's St. Anthony Falls Lab was published today in Nature Communications, a major scientific journal.
Wind energy is one of the fastest-growing renewable energy sources. The U.S. Department of Energy estimates energy losses in wind farms to be as high as 10-20 percent and identifies complex airflows created by the turbines as the major culprit for such losses. As wind turbines have grown to more than 100 meters tall, field research in real-world settings has become more difficult.
"In the lab we use tracer particles to measure airflows of wind turbine models in wind tunnels, but our research was extremely constrained by an inability to measure flows at the large scale," said Jiarong Hong, a UMN mechanical engineering assistant professor and lead researcher on the study. "Most researchers thought measurements of this kind at the real-world scale were impossible."
Hong, who grew up in southwest China and received his Ph.D. at Johns Hopkins University, had only seen snow a few times in his life before moving to Minnesota in 2012. He wondered if snow might be the solution to their dilemma.
"We have everything we needed in Minnesota for this research," Hong said. "We have a fully-equipped large research wind turbine at the U.S. Department of Energy-funded Eolos Wind Energy Research Center run by the University. We also have snow to serve as the particulates to measure the airflows and committed researchers and engineers to carry out such an unprecedented effort."
After a number of previous attempts when the snow was poor quality or the instruments malfunctioned in the cold weather, researchers headed to the Eolos 2.5 KW wind turbine in Rosemount, Minn., in the early morning hours of a snowstorm on Feb. 22, 2013.
They braved the harsh conditions in the middle of the night to set up a large searchlight with specially designed reflecting optics to generate a gigantic light sheet next to the 130-meter-tall wind turbine for illuminating the snow particles in a 36-meter-wide-by-36-meter-high area. The snow is easier to see in the light at night, much like the average person looks into a streetlight to see how much it is snowing during a snowstorm. Researchers videotaped the snow particles as the wind turbine spun to show airflow patterns. This video was digitized and synchronized with wake flow and load data from the fully instrumented research wind turbine.
To view the video, visit http://z.umn.edu/windvideo.
Results of the experiment showed that this technique was successful in measuring the turbulence of the airflow structure around the wind turbine. It is a first step in showing significant differences in the patterns of airflows in the field at large scale compared to those measured in the lab.
"These measurements are extremely important in our efforts to improve the efficiency of wind energy that will reduce our reliance on fossil fuels," said Fotis Sotiropoulos, co-author of the study and director of the University's St. Anthony Falls Lab and the Eolos Wind Energy Research Center. "Who would have ever thought we'd use a Minnesota blizzard to help fight global warming."
In addition to Hong and Sotiropoulos, other University of Minnesota researchers who were part of this study include civil engineering assistant professor Michele Guala, mechanical engineering Ph.D. student Mostafa Toloui, civil engineering Ph.D. student Kevin Howard, mechanical engineering student Sean Riley, St. Anthony Falls Lab engineer James Tucker, and former post-doctoral researcher Leonardo Chamorro who is now at the University of Illinois at Urbana-Champaign.
To view the full research paper in Nature Communications, visit z.umn.edu/windstudy14.
Rhonda Zurn | Eurek Alert!
Cooling buildings with solar heat
26.09.2016 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
Philippines’ microsatellite captures best-in-class high-resolution images
22.09.2016 | Hokkaido University
Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.
Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...
At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.
In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...
23.09.2016 | Event News
20.09.2016 | Event News
16.09.2016 | Event News
27.09.2016 | Information Technology
27.09.2016 | Machine Engineering
27.09.2016 | Physics and Astronomy