Gas Turbine Blade Trailing Edge Thickness Gradient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbomachines experience flow losses and stress peaks at the trailing edges of rotor blades and stator vanes due to abrupt material changes, which affect the efficiency of energy transfer and conversion.
Innovation Solution
The trailing edge of the airfoil has a varying wall thickness, with a thinner platform-distal region and thicker platform-proximal regions, and a continuous transition between them, reducing stress and improving flow-off conditions without mechanical or thermal stress peaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the trailing edge has a uniform wall thickness, then the structure is simple to manufacture, but flow losses increase and stress peaks occur at the trailing edge
Solution Approach 1:
The trailing edge is designed with non-uniform wall thickness, where the wall thickness varies along the radial longitudinal extent. Specifically, the platform-distal region has a smaller maximum wall thickness (0.2-0.4 mm) compared to the platform-proximal regions (0.4-0.6 mm), optimizing flow characteristics locally while maintaining structural integrity where needed
2Loss of energy
If the trailing edge wall thickness is reduced in the platform-distal region, then flow-off conditions improve, but mechanical stress peaks may occur at the transition to platforms
Solution Approach 1:
The wall thickness parameter is continuously varied along the radial longitudinal extent of the trailing edge. The continuous transition region ensures that the wall thickness changes smoothly from the platform-proximal to platform-distal regions, avoiding abrupt changes that would cause stress concentrations while still achieving the flow optimization benefits of reduced thickness in the distal region
3Loss of energy
If the trailing edge has a thinner wall thickness in the platform-distal region, then flow losses are reduced, but the structural strength may be compromised
Solution Approach 1:
The trailing edge structure is optimized with different wall thickness characteristics in different regions: the platform-distal region has reduced wall thickness (0.2-0.4 mm) for flow optimization, while the platform-proximal regions maintain greater wall thickness (0.4-0.6 mm) for structural strength, with a continuous transition region connecting these zones
Solution Approach 2:
The wall thickness variation is implemented along the radial longitudinal extent dimension, creating a gradient structure that optimizes both flow characteristics and structural strength by distributing material strategically along this dimension rather than using a uniform thickness
Data Source
AI summary
A blade, in particular a rotor blade or a stator vane, for a gas turbomachine, in particular a turbojet engine, the blade having an airfoil (1) for deflecting a flow of working fluid and a first platform (3) connected thereto, in particular integrally connected thereto, to radially bound a flow duct for the working fluid, the airfoil having a suction side and a pressure side (1.1) which are connected at a leading edge (1.2) and at a trailing edge (1.3). The trailing edge has a first minimum wall thickness in a first region (A) of a radial longitudinal extent (R) of the airfoil proximal to the first platform (3), and a maximum wall thickness that is smaller than the first minimum wall thickness in a platform-distal region (C) of the radial longitudinal extent.