Turbine Blade Bowed Tip Design for Vibration and Oxidation Resistance

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Solution Overview

Problem

Recent advances in aerodynamically high-performing, high-pressure turbine blades, particularly at the tip, have increased design difficulties due to complex multidisciplinary considerations involving aerodynamics, durability, and manufacturability.

Innovation Solution

The design incorporates a bowed tip portion on the airfoil that is bowed in both the circumferential and axial downstream directions, with specific angles and curvilinear profiles to reduce vulnerability to damaging vibrations and oxidation, while maintaining aerodynamic performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If aerodynamically high-performing, high-pressure turbine blades are designed with advanced tip configurations, then aerodynamic performance is improved, but design difficulty and manufacturing complexity increase

Engineering Contradiction:
Improveaerodynamic performanceVSAvoiddesign difficulty
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The turbine blade tip employs a bowed configuration with specific curvature in both the spanwise and chordwise directions. The bowing angle varies along the span, creating a curved geometry that improves aerodynamic performance by reducing tip leakage losses while managing the complexity through defined geometric parameters rather than arbitrary shapes

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Productivity

If turbine blade tip is designed with complex aerodynamic features, then aerodynamic performance is improved, but vulnerability to vibrations and oxidation increases

Engineering Contradiction:
Improveaerodynamic performanceVSAvoidvulnerability to vibrations and oxidation
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The bowed tip design applies different geometric characteristics to different regions of the blade tip. The bowing angle and curvature are specifically tailored for the tip region where aerodynamic losses occur, while maintaining simpler geometries in other regions. This localized optimization improves aerodynamic performance without uniformly increasing vulnerability across the entire blade

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The curved bowed configuration at the tip reduces stress concentrations compared to sharp edges, and the specific bowing geometry is designed to minimize exposure to oxidative environments while maintaining aerodynamic effectiveness

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If turbine blade tip geometry is optimized for aerodynamic performance, then efficiency is improved, but manufacturability becomes more difficult

Engineering Contradiction:
Improveaerodynamic efficiencyVSAvoidmanufacturability
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The bowed tip geometry is defined by specific mathematical relationships and parameter ranges (bowing angle, curvature radius, spanwise distribution) that allow for controlled manufacturing. The curvature is continuous and smooth, avoiding sharp transitions that would be difficult to manufacture, while still achieving the desired aerodynamic performance

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3467260B1Turbine blade with bowed tip
Publication Date: 2024.12.25 RTX CORP
  • EP3467260B1 patent drawingFigure 1
  • EP3467260B1 patent drawingFigure 2
  • EP3467260B1 patent drawingFigure 3~4

AI summary

A component (64) for a gas turbine engine includes a platform (76) that has a radially inner side and a radially outer side. A root portion (74) extends from the radially inner portion of the platform (76). An airfoil (78) extends from the radially outer side of the platform (76). The airfoil (78) includes a pressure side that extends between a leading edge (82) and a trailing edge (84). A suction side extends between the leading edge (82) and the trailing edge (84). A bowed tip portion (100) extends perpendicular to a mid-camber line of the airfoil (78).