Wind turbine blade having a geometric sweep

Patent metadata

Field	Value
Publication number	US-9920741-B2
Application number	US-201213357661-A
Country	US
Kind code	B2
Filing date	Jan 25, 2012
Priority date	Jan 25, 2012
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A swept wind turbine blade ( 20 ) includes a blade body ( 24 ) extending along a length between a root ( 26 ) and a tip ( 28 ) of the blade ( 20 ). A pitch axis ( 36 ) extends through the root ( 26 ) of the blade ( 20 ). A reference line ( 48 ) defines a deviation from the pitch axis ( 36 ) and corresponds to a swept shape of the blade ( 20 ) along its length. The reference line ( 48 ) has a zero sweep at the root ( 26 ), a zero slope at the root ( 26 ), and a positive curvature ( 66 ) along a segment within 25% of the length from the root ( 26 ) to the tip ( 28 ) of the blade ( 20 ).

First claim

The invention claimed is:

1. A swept wind turbine blade comprising:
a blade body extending along a length between a root and a tip of the blade;
a pitch axis extending through the root of the blade;
a reference line defining a deviation from the pitch axis corresponding to a swept shape of the blade along its length;
wherein the reference line comprises:
a zero sweep at the root;
a zero slope at the root;
a positive curvature along a segment within 25% of the length from the root to the tip of the blade;

wherein the reference line comprises a positive curvature at the root.

2. The swept wind turbine blade of claim 1 , wherein the reference line further comprises:
a first curvature defined by a first function along a first portion of the length;
a second curvature defined by a second function different from the first function along a second portion of the length adjoining the first function at a transition point;
wherein a slope of the first curvature and a slope of the second curvature are equal at the transition point.

3. The swept wind turbine blade of claim 1 , wherein the reference line further comprises:
a first curvature defined by a first function along a first portion of the length;
a second curvature defined by a second function different from the first function along a second portion of the length adjoining the first function at a transition point;
wherein a slope of the first curvature and a slope of the second curvature are equal at the transition point.

4. The swept wind turbine blade of claim 3 , wherein the first curvature extends from a point on a segment having a zero slope forward of the root.

5. The swept blade of claim 1 , further comprising a negative curvature outboard from the positive curvature along the length.

6. The swept wind turbine blade of claim 1 , wherein the reference line comprises a member selected from the group consisting of an elastic axis, a quarter chord line, a center of mass line, a shear center line, a leading edge line, and a trailing edge line of the blade.

7. A wind turbine rotor comprising the swept blade of claim 1 .

8. A swept wind turbine blade comprising:
a blade body extending along a length between a root and a tip of the blade;
a pitch axis extending through the root of the blade;
a reference line defining a deviation from the pitch axis corresponding to a swept shape of the blade along its length;
wherein the reference line comprises:
a zero sweep at the root;
a zero slope at the root;
a positive curvature along a segment within 25% of the length from the root to the tip of the blade;

wherein the reference line further comprises:
a first curvature defined by a first function along a first portion of the length;
a second curvature defined by a second function different from the first function along a second portion of the length adjoining the first function at a transition point;
wherein the first curvature and the second curvature each terminate at the transition point and have an equivalent curvature.

Assignees

• Obrecht John M
• Gilling Lasse
• Hansen Henrik Fredslund
• Johnson Scott J
• Sievers Ryan A
• Siemens Ag

Inventors

• Obrecht John M
• Gilling Lasse
• Hansen Henrik Fredslund
• Johnson Scott J
• Sievers Ryan A

Classifications

• F03D1/0675 Primary

  of the blades · CPC title

• F05B2240/311

  flexible or elastic · CPC title

• Y02E10/721

  Cross-Sectional Technologies · mapped topic

• F05B2250/71

  curved · CPC title

• F05B2200/222

  Cubic power · CPC title