Wind Turbine Rotor Blade Trailing Edge Transition Strength

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Solution Overview

Problem

Rotor blades with trailing edge closure webs face challenges in achieving sufficient strength, particularly at the transition area between the closure web and the rotor blade half-shell, where high loads are encountered.

Innovation Solution

A rotor blade design featuring a laminate sandwich construction with core materials of varying specific densities, where a higher-density foam is used along the transition region between the trailing edge closure web and the rotor blade half-shell, and additional strips with even higher densities are integrated for enhanced strength, increasing the thickness and stability of the trailing edge closure web.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a uniform density core material is used throughout the trailing edge rib, then the manufacturing process is simple, but the strength in the transition area is insufficient

Engineering Contradiction:
Improvestrength in transition areaVSAvoidcore material density variation
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies local quality by using core materials with different specific densities in different regions of the trailing edge rib. The first core material with lower specific density is used in the first region, while the second core material with higher specific density is used in the second region, optimizing strength where needed without unnecessary material elsewhere.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining different core materials with varying specific densities within the same component. This allows the trailing edge rib to have regions of different stiffness and strength characteristics, matching the varying load requirements along the rib structure.

Inventive Principle:
Principle #40Composite materials

2Strength

If higher density core material is used throughout the entire trailing edge rib, then the strength is maximized, but the manufacturing cost increases

Engineering Contradiction:
Improveoverall strengthVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

Instead of using high-density material throughout, the patent applies high-density core material only in the second region where high strength is required, while using lower-density material in the first region. This localized approach achieves necessary strength without maximizing cost.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the density parameter of the core material along the length of the trailing edge rib. By varying the specific density from the first region to the second region, the design optimizes the strength-to-cost ratio, using more expensive material only where structurally necessary.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the trailing edge rib thickness is increased, then the strength and stability are improved, but the weight and material consumption increase

Engineering Contradiction:
Improvestrength and stabilityVSAvoidweight of trailing edge rib
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent implements local quality by varying the core material density along the rib length rather than uniformly increasing thickness. The higher-density material provides the necessary strength and stability in critical areas without requiring a uniform increase in rib thickness that would unnecessarily increase weight throughout the entire structure.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design significantly enhances the strength of the rotor blade in the transition area, effectively managing high loads and improving the structural integrity of the trailing edge, while maintaining cost-effectiveness through the use of lower-density foams in less stressed areas.

Implementation Method 1

The first and second core materials are primarily first and second foams that absorb resin systems during the lamination process, for example, through vacuum infusion.

Methodology Applied
Scientific EffectVacuum infusion:

Data Source

PatentEP3299613B1Rotor blade with termination flange
Publication Date: 2020.01.08 SENVION GMBH
  • EP3299613B1 patent drawingFigure 1
  • EP3299613B1 patent drawingFigure 2

AI summary

The invention relates to a rotor blade for a wind turbine with a trailing edge termination web (2) arranged between a suction-side and a pressure-side rotor blade half-shell (1), characterized in that the trailing edge termination web (2) is designed as a laminate component in a sandwich construction with a first core material (3) having a first specific density and a second core material (4) arranged along a transition area between the trailing edge termination web (2) and the rotor blade half-shell (1), which has a second specific density, and the second specific density is greater than the first specific density.