Slat with tip vortex modification appendage for wind turbine

A wind turbine blade comprising:

• a main blade element comprising a radially inboard portion;
• a slat spaced proximate the main blade element along a radial span of the inboard portion;
• and
• a slat tip vortex reduction appendage on an end of the slat;
• wherein the vortex reduction appendage comprises a winglet extending from an end of the slat in a direction away from the main blade element;
• and
• wherein a line is defined at a leading edge of the main blade element perpendicular to a mean camber line of the main blade element, and the slat is disposed wholly behind said line and spaced from a suction side of the inboard portion of the main blade element throughout a radial span of the slat.

A wind turbine blade comprising:

• a main blade element comprising a radially inboard portion;
• a slat spaced proximate the main blade element along a radial span of the inboard portion;
• and
• a slat tip vortex reduction appendage on an end of the slat;
• wherein at least a portion of a leading edge of the slat is disposed within a zone of parallel flow wherein an operational airflow flows parallel ±6° to a suction side of the main blade element throughout a variation of at least 8° in an inflow angle to the main blade element.

A wind turbine blade comprising:

• a main blade element comprising a radially inboard portion;
• and
• a slat spaced proximate the main blade element along a radial span of the inboard portion;
• wherein a line is defined at a leading edge of the main blade element perpendicular to a mean camber line of the main blade element, and the slat is disposed behind said line and spaced from a suction side of the inboard portion of the main blade element throughout a radial span of the slat;
• and
• wherein at least a leading edge of the slat is disposed within a zone of reduced inflow angle variation, wherein, when an angle of an operational air inflow to the main blade element changes by N degrees relative to a chord line of the main blade element, an angle of a resultant air inflow to the slat changes by only up to 2N/3 degrees relative to a chord line of the slat throughout a variation of at least 8° in an inflow angle to the primary blade element.