Turbomachine Blade Row With Wavy Side Wall Contour

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Solution Overview

Problem

In turbomachines, secondary flows or channel vortices form due to differences in pressure gradients across blade cascades, leading to increased pressure losses and reduced efficiency.

Innovation Solution

The implementation of wavy sidewall contouring in blade channels with multiple elevations and depressions, which influence primary pressure gradients and outflow angles, reducing secondary flow vortices and improving flow distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional smooth side walls are used in blade channels, then the structure is simple and easy to manufacture, but secondary flows and channel vortices form due to pressure gradients, leading to increased pressure losses and reduced efficiency

Engineering Contradiction:
Improvepressure lossesVSAvoidside wall contour complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The side wall contour is designed with wave-like curvature featuring multiple elevations and depressions instead of a smooth surface. This curvature modification influences the pressure gradient distribution and reduces secondary flows, directly addressing the energy loss problem while accepting increased geometric complexity

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The side wall contour introduces local variations in the form of elevations and depressions at specific positions along the side wall. These local geometric modifications create favorable pressure gradients in critical regions, reducing secondary flows and improving overall flow distribution without requiring complete redesign of the entire blade channel

Inventive Principle:
Principle #3Local quality

2Productivity

If wave-like side wall contouring with elevations and depressions is implemented, then secondary flows are reduced and outflow angle alignment is improved, but the side wall contour becomes more complex

Engineering Contradiction:
Improveturbomachine efficiencyVSAvoidside wall contour complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The wave-like contour with elevations and depressions modifies the side wall geometry to influence pressure gradients and improve flow characteristics. This curvature approach enhances productivity by reducing secondary flows and improving outflow angle alignment, while the complexity is managed through systematic contour design

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The side wall contour parameters such as elevation height, depression depth, wavelength, and position are optimized to achieve the desired flow control. By adjusting these geometric parameters, the system improves turbomachine efficiency while maintaining manufacturable complexity levels

Inventive Principle:
Principle #35Parameter changes

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 reduces secondary flows and enhances the alignment of the outflow angle, resulting in improved turbomachine efficiency without inducing additional vortices or mixing losses.

Implementation Method 1

A primary or main flow guided through a flow channel is deflected by a lateral pressure gradient parallel to the boundary wall

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

Since flow layers near the wall are deflected more strongly than those further away due to their lower velocity, a secondary flow or channel vortex is formed

Methodology Applied
Scientific EffectSecondary flow:

Implementation Method 3

A primary or main flow guided through a flow channel is deflected by a lateral pressure gradient parallel to the boundary wall

Methodology Applied
Scientific EffectBoundary layer: Boundary Layer

Data Source

PatentEP2835499B1Blade row and corresponding flow machine
Publication Date: 2019.10.09 MTU AERO ENGINES GMBH
  • EP2835499B1 patent drawingFigure 1
  • EP2835499B1 patent drawingFigure 2~3
  • EP2835499B1 patent drawingFigure 4~5

AI summary

A blade grid of a turbomachine is disclosed, the circumferential side wall of which is wave-like and has at least two protrusions and at least one depression or at least two depressions and at least one protrusion, as well as a turbomachine with such a blade grid.