Non Axis-Symmetric Stator Vane Endwall Contouring

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Solution Overview

Problem

In gas turbine engines, traditional stator vane airfoil designs suffer from inefficient flow control due to secondary flow and endwall roll-up effects, leading to flow separation and dynamic losses, particularly at the inner and outer endwalls.

Innovation Solution

Implementing non-axisymmetric endwall contouring on both inner and outer endwalls, which varies radially and circumferentially, reduces secondary flow effects and increases diffusion capability without compromising loading capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional axis-symmetric endwall contours are used, then manufacturing is simpler, but flow separation and dynamic losses increase due to secondary flow and endwall roll-up effects

Engineering Contradiction:
Improvedynamic lossesVSAvoidendwall contour complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by transitioning from traditional axis-symmetric endwall contours to non-axisymmetric endwall contours. The endwall contour is designed with different radial positions at different circumferential positions, creating an asymmetric geometry that actively counteracts the symmetric secondary flow patterns and endwall roll-up effects, thereby reducing flow separation and dynamic losses in the stator vane airfoil flowpath.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent implements local quality by varying the endwall contour radially and circumferentially to create different geometric properties at different locations. The non-axisymmetric contour provides locally optimized flow control characteristics in high-loss regions while maintaining simpler geometry in other areas, allowing targeted reduction of secondary flow effects without uniformly increasing overall device complexity.

Inventive Principle:
Principle #3Local quality

2Productivity

If non-axisymmetric endwall contouring is implemented, then flow separation and dynamic losses are reduced, but manufacturing complexity increases

Engineering Contradiction:
Improveflow control efficiencyVSAvoidendwall contour fabrication
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by modifying the geometric parameters of the endwall contour from a uniform axis-symmetric configuration to a varied non-axisymmetric configuration. The contour is defined by specific radial positions at different circumferential positions, creating a parameterized geometry that improves flow control efficiency while maintaining manufacturability through controlled geometric variation rather than arbitrary complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2589752B2Non Axis-Symmetric Stator Vane Endwall Contour
Publication Date: 2024.11.27 RTX CORP
  • EP2589752B2 patent drawingFigure 1
  • EP2589752B2 patent drawingFigure 2
  • EP2589752B2 patent drawingFigure 3A~3B

AI summary

An airfoil (42) comprises pressure and suction surfaces (48, 47) extending axially from a leading edge (45) to a trailing edge (46) and radially from a root section (49) to a tip section (50), defining a mean span therebetween. An inner endwall (43) defines an inner endwall contour extending axially and circumferentially from the root section, and an outer endwall (44) defines an outer endwall contour extending axially and circumferentially from the tip section. The inner and outer endwall contours are defined by varying radial deviations from circumferentially uniform nominal inner and outer radii, where one of the radial deviations varies axially and circumferentially by at least three percent of a mean span of the airfoil.