Edgeless Vortex Generator Turbine Blade Design

Solution Overview

Problem

Existing blade constructions for low-pressure turbines with sharp-edged turbulators face manufacturing challenges, reduced service life, and increased frictional losses at high Reynolds numbers, making them impractical for engine applications.

Innovation Solution

A blade construction with an undulating, edgeless vortex generator featuring surface undulations in the form of waves along the inlet-side profile, which promotes a timely laminar-turbulent transition without sharp edges, enhancing manufacturability, service life, and reducing frictional losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sharp-edged turbulators are used to promote laminar-turbulent transition, then the transition is achieved at higher altitudes with improved profile loss, but frictional losses increase near the ground and manufacturing complexity increases

Engineering Contradiction:

Improveprofile loss reductionVSAvoidfrictional losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces sharp-edged turbulators with rounded, curved surface undulations that have no sharp edges. The vortex generator features smooth, continuous curvature throughout its structure, eliminating the sharp leading edges that cause high frictional losses while maintaining the ability to promote laminar-turbulent transition effectively across different flight conditions.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the geometric parameters of the turbulator from sharp-edged projections to rounded undulations with specific curvature radii. The surface undulations have controlled amplitude and wavelength parameters that are optimized to achieve effective flow transition while minimizing frictional resistance, representing a fundamental parameter change in the turbulator design.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If sharp-edged turbulators are used to control boundary layer transition, then the flow transition is improved, but manufacturing precision requirements increase and service life decreases

Engineering Contradiction:

Improveflow transition controlVSAvoidedge sharpness precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces sharp-edged turbulators with rounded, curved surface undulations that have no sharp edges. The vortex generator features smooth, continuous curvature throughout its structure, eliminating the sharp leading edges that cause high frictional losses while maintaining the ability to promote laminar-turbulent transition effectively across different flight conditions.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Reliability

If sharp-edged turbulators are used to reduce separation bubble, then the separation control is improved, but the blade stress increases and service life is reduced

Engineering Contradiction:

Improveseparation controlVSAvoidblade stress resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent replaces sharp-edged turbulators with rounded, curved surface undulations that have no sharp edges. The vortex generator features smooth, continuous curvature throughout its structure, eliminating the sharp leading edges that cause high frictional losses while maintaining the ability to promote laminar-turbulent transition effectively across different flight conditions.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 edgeless vortex generator improves manufacturability and service life while reducing frictional losses and engine noise, allowing for direct integration into the blade fabrication process, achieving a 10-20% reduction in pressure amplitude and improved flow behavior.

Implementation Method 1

The transition from the laminar boundary layer to the turbulent boundary layer (also called transition range) depends in this case on a series of influencing variables, among them the surface roughness of the profile wall being flowed around

Methodology Applied

Scientific EffectLaminar-turbulent transition: Turbulence

Implementation Method 2

the boundary layer originates from the wall friction of the flowing particles and forms the flow-related bridge between the profile and the ideal flow

Methodology Applied

Scientific EffectBoundary layer: Boundary Layer

Implementation Method 3

Influencing a flow, especially the boundary layer close to the surface, through a vortex generator (also called turbulators) is a much investigated topic

Methodology Applied

Scientific EffectVortex generator: Vortex Ring

Data Source

PatentUS8814529B2Blade for a turbo device with a vortex-generator

Publication Date: 2014.08.26 MTU AERO ENGINES GMBH

AI summary

A blade construction for a turbo device, preferably a blade array of a low-pressure turbine, is disclosed. On the inlet-side profile surface of the blade a vortex generator is arranged downstream from the speed maximum. The vortex generator is formed by a surface undulation with at least one wave, the wave tail of which runs in the form of a wave trough and/or a wave peak in the blade vertical direction.