In the long sprint to find new sources of clean, low-cost power, slow and steady might win the race -- the slow-moving water of currents and tides, that is. Just as wind turbines tap into the energy of flowing air to generate electricity, hydrokinetic devices produce power from moving masses of water.
This image shows velocity and pressure around a string of submerged blades.
In a paper appearing in AIP Publishing's Journal of Renewable and Sustainable Energy, Ramon Fernandez-Feria, a professor of fluid mechanics at Universidad de Málaga in Spain, and his colleagues Joaquin Ortega-Casanova and Daniel Cebrián performed a computer simulation to determine the optimum configuration of one such system to enable it to extract the maximum amount of energy from any given current.
The system, developed by a Norwegian company called Tidal Sails AS, consists of a string of submerged blades or sails, connected via wire ropes, angled into the oncoming current. The rushing current generates large lift forces in the sails, and as they are pushed along through a continuous loop, they drive a generator to produce electricity.
A small-scale version of the Tidal Sails device is already in operation at a test facility constructed in a stream outside Haugesund, Norway. The pilot project has a power-producing capacity of 28 kilowatts; a full-scale version could generate several megawatts of power. Installing several such units in a tidal stream, the company says, could generate as much as 100 gigawatts of electricity per year.
In their analysis, the researchers found that the maximum amount of power could be generated using blades with a chord length (the width of the blade at a given distance along its length) equal to the separation between each individual blade, that are positioned at about a 79 degree angle relative to the oncoming current, and that move at a speed about one and half times faster than the current.
"The next step would be to refine the design of the device with further hydrodynamic numerical simulations, complemented with small-scale experiments," Fernandez-Feria said. "For instance, trying more efficient aerodynamic blade profiles, and different angles between the string of blades and the current."
The article, "Lift and drag characteristics of a cascade of flat plates in a configuration of interest for a tidal current energy converter: Numerical simulations analysis" by Daniel Cebrián, Joaquin Ortega-Casanova and Ramon Fernandez-Feria appears in the Journal of Renewable and Sustainable Energy. See: http://dx.doi.org/10.1063/1.4816495
ABOUT THE JOURNAL
The Journal of Renewable and Sustainable Energy is an interdisciplinary, peer-reviewed journal produced by AIP publishing that covers all areas of renewable and sustainable energy-related fields that apply to the physical science and engineering communities. See: http://jrse.aip.org/
Jason Socrates Bardi | EurekAlert!
When a fish becomes fluid
17.12.2018 | Institute of Science and Technology Austria
Some brain tumors may respond to immunotherapy, new study suggests
11.12.2018 | Columbia University Irving Medical Center
Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
18.12.2018 | Materials Sciences
18.12.2018 | Physics and Astronomy
18.12.2018 | Physics and Astronomy