The primary application of wind turbines is to generate energy using the wind.
Hence, the aerodynamics is a very important aspect of wind turbines. Like most
machines, wind turbines come in many different types, all of them based on different
energy extraction concepts.
Though the details of the aerodynamics depend very much on the topology, some
fundamental concepts apply to all turbines. Every topology has a maximum power
for a given flow, and some topologies are better than others. The method used to
extract power has a strong influence on this. In general, all turbines may be classified
as either lift-based or drag-based, the former being more efficient. The difference
between these groups is the aerodynamic force that is used to extract the energy.
Vertical axis wind turbines represent a new type of power-generating technology designed for a smaller niche urban market. Generally, VAWT’s would have a fairly low visual and environmental impact around buildings as they are shorter in height than the traditional horizontal wind turbine. Also, their main working components, such as the generator and gearbox are located closer to the ground requiring less structural supports.
This makes maintenance, inspection and repair of these turbine generators fairly easy.
Vertical Axis Wind Turbines (VAWTs) represent a unique form of power-generating technology, they are typically small wind turbines that are characterized by an axis of rotation that is perpendicular to the ground.
As a result, VAWTs can operate independently of wind direction, which is a major advantage for urban applications where wind direction can change rapidly. The two primary VAWT designs are derived from either the Darrieus (lift-driven) or the Savonius (drag-driven) rotors.