Vertical Axis Windmill Airfoil Drag Reduction

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Solution Overview

Problem

Conventional windmills are ineffective in producing energy at wind speeds below 10 mph, limiting their operational efficiency and energy production in areas with average wind speeds of 9 mph or less, as seen in localities like McKinney, Tex., where wind speeds are consistently low.

Innovation Solution

A vertical axis windmill design featuring three or more frames rotatable about a vertical axis, with hingedly affixed airfoils that can swing open to reduce drag and maximize energy capture, along with adjustable stops and counterbalance mechanisms to optimize energy production in low wind conditions, and integrated electrical or hydraulic generators for energy conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional windmills are used, then they can operate in high wind conditions (15-30+ mph), but they produce little or no energy when winds are below 10 mph

Engineering Contradiction:

Improveenergy productionVSAvoidoperational effectiveness in low wind

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The airfoils are made dynamically movable through hinged attachments to the frames, allowing them to swing between closed and open positions based on wind conditions. This dynamic adjustment enables the windmill to capture energy effectively in low wind speeds by opening airfoils to reduce drag, while maintaining operational capability in high wind speeds by closing airfoils to maximize wind resistance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the operational parameters of the airfoils by allowing their angle and position relative to the frames to vary. In low wind conditions (below 10 mph), airfoils are positioned to minimize drag and maximize capture of weak winds. In high wind conditions (15-30+ mph), airfoils are positioned to maximize wind resistance for optimal energy generation. This parameter adjustment resolves the contradiction between productivity in low wind and reliability across all conditions.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If windmill blades are made taller to reach higher wind speeds, then energy production improves in high wind areas, but complexity and cost increase

Engineering Contradiction:

Improveenergy productionVSAvoidturbine blade height

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

Instead of increasing blade height (vertical dimension) to access higher winds, the invention operates in the horizontal dimension by using multiple frames rotating about a vertical axis with adjustable airfoils. This dimensional approach allows the windmill to capture energy from lower, more accessible wind speeds through dynamic airfoil adjustment, avoiding the complexity and cost of taller structures while maintaining productivity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Power

If airfoils are fixed in closed position, then wind resistance is maximized for energy capture, but drag increases in low wind conditions

Engineering Contradiction:

Improvewind resistanceVSAvoiddrag

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The airfoils are dynamically positioned based on wind speed conditions. In low wind conditions, airfoils swing open to minimize drag and allow the lightweight vertical axis structure to rotate easily, capturing even weak winds. In higher wind conditions, airfoils close to maximize wind resistance and power generation. This dynamic positioning resolves the contradiction between maximizing power through wind resistance and minimizing energy loss through drag.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention converts the potentially harmful effect of drag in low wind conditions into a beneficial feature by opening the airfoils. What would normally be considered a loss (drag) is actually utilized to enable rotation in low wind speeds, allowing the windmill to operate productively in conditions where conventional fixed-blade windmills would fail to generate energy.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

The vertical axis windmill effectively operates in 9 mph or less wind conditions, enhancing energy production and operational efficiency by minimizing drag and maximizing wind resistance, allowing for consistent energy generation throughout the year.

Implementation Method 1

hingedly affixed airfoils that can swing open to reduce drag and maximize energy capture

Methodology Applied

Scientific EffectDrag reduction: Drag

Implementation Method 2

vertical axis windmill design featuring three or more frames rotatable about a vertical axis, with hingedly affixed airfoils that can swing open to reduce drag and maximize energy capture

Methodology Applied

Scientific EffectWind power conversion: Wind Power

Data Source

PatentUS10041478B2Vertical axis windmill

Publication Date: 2018.08.07 SPENCER GEORGE AUTHER

AI summary

A vertical axis windmill comprises three or more frames rotatable in unison about a substantially vertical axis and a plurality of airfoils hingedly affixed to each frame. Each airfoil is able to swing away from its respective frame in a first direction from a closed position to an open position and not able to swing away from its respective frame in a second direction from the closed position.