Active Flow Control opens up major opportunities for increasing the efficient utilization of wind power.
The development of a turbine providing increased performance efficiencies at lower wind speeds and with significantly reduced noise levels will enable the positioning of wind turbines also in built-up areas.
“Wind is one of the cleanest sources of natural energy provided by nature,” says Professor Avi Seifert of the Tel Aviv University School of Mechanical Engineering.
Wind energy is closely related to solar energy since winds are created by the solar heating of the atmosphere. Current technology for producing power from wind is not as effective as it could be, as wind turbines work efficiently only within a certain range of wind speeds. This shortcoming limits the efficient functioning of the units and also poses serious limitations on where they can be placed. Professors Seifert. Miloh and Kribus are working on the development of a wind turbine that will be capable of working efficiently at much lower speeds. This technology, known as Active Flow Control, has been in development at the Tel Aviv University’s Meadow Aerodynamics Laboratory for over two decades and, as Seifert explains, “is able to alter the air flow at the turbine blade surface with a small input of energy in the right place and at the right time, producing an increase in overall performance.” When working at maximum efficiencies, wind turbines using Active Flow Control technology could be placed in areas of lower wind speeds, thus opening up a wider range of possibilities and opportunities for the use of wind power.
Another drawback is the high levels of noise produced by existing turbines, making it almost impossible to place wind turbines in or near residential areas. Seifert, in collaboration with Professor Tuvia Miloh of the School of Mechanical Engineering, their PhD student Oksana Stalnov and another scholar Dr. Thorsten Lutz at the University of Stuttgart, Germany, are working on reducing the noise levels of wind turbines using Active Flow Control. This would allow for turbines to be placed in and around built-up areas without causing a disturbance.
Seifert sees wind as a clean source of energy with enormous potential, untapped in many places as in Israel. “With increased levels of efficiency, wind turbines could be smaller in size, quieter and more flexible, allowing them to be placed closer to homes. This would significantly increase our ability to harness energy from wind,” Seifert concludes.
Another major area of application for the Active Flow Control technology, under development at Prof. Seifert’s laboratory, is reducing the aerodynamic drag (resistance) of large trucks driving at high speeds on the freeways, thereby significantly improving their fuel efficiency.