The strong winds in the UK over the last few weeks serve as a timely reminder that whatever we build needs to be able to withstand exceptional natural forces. Load cells have long played their part in the construction, and increasingly in the continual monitoring, of wind-resistant structures (see our story on the Ordsall Chord Bridge, for example).
Harnessing the wind
There will no doubt be an increasing demand for this level of monitoring as the world looks towards building structures for harnessing natural forces to generate power, including wind turbines. As an article in Science Times explains, load cells are key to keeping wind turbines turning efficiently.
“Some of the world’s largest wind farms rely on load cell sensors to keep their turbines operate at optimal performance by increasing reliability and reducing downtime. These load cells can measure vibration, bolt tightness, torque, strain, noise, and so many more aspects of turbine performance.”
However, a (literally) small issue might scupper this. Wind-born small particles such as dirt and salt can attach themselves to the blades, reducing the output by as much as 15%. Quoted in the same article, Rich Barnes, Executive Vice President at DNV GL, said:
“Increasing the performance of wind turbines and blades is crucial for the transition to a cleaner energy system. Erosion of blades is affecting the global wind industry.”
Load cells and wind turbines
Load cells can play their part through the ongoing accumulation and analysis of data on the performance of the turbine. With big data to work with, software analysis can spot any unusual patterns that emerge, which may not have been spotted with readings taken at longer intervals. To see just how effective renewable wind energy can be, you need look no further than the island of Orkney. According to The Guardian:
“Orkney was once utterly dependent on power that was produced by burning coal and gas on the Scottish mainland and then transmitted through an undersea cable. Today the islands are so festooned with wind turbines, they cannot find enough uses for the emission-free power they create on their own.”
Pedalling into the wind
Wind tunnels have been used to test drag and other factors for a whole range of vehicles. It’s a testament to the rise in popularity of cycling that cycling hero Chris Boardman decided to partner with Boardman Bikes (now owner by Halfords) to build the UK’s first cycle-specific wind tunnel in Evesham. Kieron Salter, managing director of business partner KWSP, explained why in an article for Eureka magazine:
“There are really only a few wind tunnels you can use, the Formula One tunnels like Williams, Mercedes or McLaren, there’s Southampton University’s wind tunnel and that’s really about it. The amount of time available is so limited and is expensive. It’s thousands of pounds an hour as opposed to with our tunnel where it could be hundreds of pounds an hour.”
Curries and cycling
Boardman was reported to have said that he wanted to offer people use of a wind tunnel for the price of a good curry. A sessions will actually cost close to £200, but that’s still a massive saving (albeit an expensive curry!). The tunnel opened last year to the public after a six month test period for all the tunnel components including load cells, data acquisition systems, control systems and electrical systems.
The cycle is set up on a platform in the middle of a test room, and set in front of the wind tunnel’s opening. The platform sits on four load cells which measure, calibrate and cancel out the vertical force and movement made by the rider when they pedal. There is also an extra load cell, as Salter explained:
“At the back is a load cell that measures drag, there are also two side force ones because the air flow is never regular around the athlete and as we yaw it we’re able to take out the impact of side force.”
Gull wings in wind tunnels
Wind tunnels are also being used by a team at the University of Toronto’s Institute of Aerospace Studies (UTIAS) to study the way gulls adapt their wing shape to make their flight more stable. The team acquired gull corpses from rescue organisations, and prepared wings that could be put into a variety of poses. As an article in Aerospace Testing International explained:
“The wings were tested at 10 m/s (22mph) in the 1.2m wide by 0.8m high and 5m long wind tunnel (4ft x 2.6ft x 16ft), to provide the nominal range or Reynolds number conditions that the gulls experience during glide, about 90,000 to 180,000 depending on the wing size. Researchers measured the lift, drag and pitch moments of 12 different wing shapes using a load cell mounted at the root of the wings.”
Results show that gulls adapt their wing shape when soaring. The hope is that the research will inform the design of future aircraft to have wings that can change shape whilst soaring, and take advantage of so-called energy harvesting.
Need load cells for your next wind-driven project?
Contact us first. We design and manufacture our own load cells right here in the UK for a diverse range of clients. So, whatever you require, call us for expert advice and information. We’re happy to help and no deceased gulls are required.