| 摘要 |
A turbine has airfoils that are configured to extract work from a prevailing fluid flow. An actuator causes the airfoils to pivot or fold between a first position with their spans substantially normal to the flow direction and a second position with their spans substantially parallel to the flow direction, or any position in between. The variable geometry allows the airfoils to be sized for relatively light winds and to remain operational in relatively high winds without damage. Under extreme conditions the airfoils may be folded completely for safety. |
