Vortex Generator Placement Using Stall Flags

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Solution Overview

Problem

Existing wind turbine installations often lack necessary aerodynamic information for optimizing vortex generator placement, making it difficult to increase electricity generation capacity without costly and complex equipment or analyses, especially for existing systems with unknown aerodynamic characteristics.

Innovation Solution

A low-cost, non-permanent method using stall flags to determine optimal vortex generator placement on wind turbine blades, followed by a custom template for precise installation, allowing for efficient airflow mixing and increased electricity production without extensive empirical testing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If wind tunnel simulations or computer simulations are used to determine optimal vortex generator placement, then manufacturing precision and reliability improve, but device complexity and cost increase significantly

Engineering Contradiction:

Improvevortex generator placement precisionVSAvoidsimulation equipment complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses disposable stall flags instead of expensive, complex simulation equipment. The flags are simple, inexpensive objects that can be attached to the blade, observed during operation to identify stall conditions, and then discarded. This provides the necessary aerodynamic information without requiring costly wind tunnel or computer simulations.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The turbine blade itself serves the dual purpose of generating power and providing aerodynamic data. By observing stall conditions directly on the operating blade through the stall flags, the system uses its own operational behavior to determine optimal vortex generator placement, eliminating the need for external simulation facilities.

Inventive Principle:

Principle #25Self-service

2Manufacturing precision

If extensive empirical testing is conducted to determine optimal vortex generator placement, then manufacturing precision improves, but loss of time and productivity decrease

Engineering Contradiction:

Improvevortex generator placement precisionVSAvoidtesting time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary identification of stall conditions using simple stall flags before installing the final vortex generator system. This preliminary action provides the necessary aerodynamic information early in the process, allowing direct placement of vortex generators without requiring subsequent extensive empirical testing to verify optimal positions.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If static devices like vortex generators are used instead of active control technologies, then device complexity and cost decrease, but manufacturing precision requirements increase

Engineering Contradiction:

Improvecontrol system complexityVSAvoidvortex generator placement precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent uses inexpensive stall flags to achieve precise aerodynamic measurements, enabling accurate determination of vortex generator placement without complex active control systems. The simplicity of the flags contrasts with the precision they enable in the final vortex generator installation.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 method enables the identification of optimal vortex generator placement on wind turbine blades, enhancing airflow mixing and delaying stall conditions, leading to increased electricity production by 3%-7% at mid-range wind speeds, while minimizing installation time and cost.

Implementation Method 1

They are employed to increase the efficiency of an airfoil by creating vortices on the low pressure side of an airfoil that will introduce energy into the boundary layer adjacent the surface

Methodology Applied

Scientific EffectVortex generation: Vortex Ring

Implementation Method 2

introduce energy into the boundary layer adjacent the surface, thereby moving downstream the point at which the boundary layer will break away from the surface

Methodology Applied

Scientific EffectBoundary layer: Boundary Layer

Implementation Method 3

Corten, the point of separation is indicated, when the turbine blade is operating, by the flap-like members being caused to rotate on their hinges by a backwards airflow behind the separation point

Methodology Applied

Scientific EffectFlow separation: Flow Separation

Data Source

PatentUS8746053B2Method for determining optimum vortex generator placement for maximum efficiency on a retrofitted wind turbine generator of unknown aerodynamic design

Publication Date: 2014.06.10 INVENTUS HOLDINGS LLC

AI summary

A method of optimizing performance of a wind turbine electric generator (WTG) comprises the steps of measuring the performance of a wind turbine electric generator, defining an area on a blade of the WTG, placing stall flags within said defined area, monitoring the behavior of the stall flags when the WTG is operating, determining a stall line based upon the stall flags during operation, installing vortex generators on the blade adjacent to and upwind of said stall line, monitoring the behavior of said stall flags during operation with vortex generators installed on all blades, and measuring the performance of the WTG to detect improved performance. If there is little or no improvement, repeating the steps on a second WTG using different placement within the defined area for the vortex generators.