Gas Turbine Airfoil Tip Plenum Cooling Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cooling air used to cool the tips of gas turbine engine blades and vanes is excessively heated before reaching the tip, reducing its effectiveness in heat transfer due to prior heating by external surfaces of the airfoil.
Innovation Solution
A blade design with a tip plenum isolated from pressure and suction side skin core passages, receiving cooling air directly from main body cavities, which are thermally and fluidly isolated from external surfaces, ensuring the cooling air remains colder and maintains high heat transfer coefficients by the time it reaches the tip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling air is routed through skin core passages to cool the airfoil surfaces, then the pressure and suction sides are effectively cooled, but the cooling air becomes excessively heated before reaching the tip
Solution Approach 1:
The cooling system is segmented into distinct functional zones: skin core passages for surface cooling and a tip plenum for tip cooling. The tip plenum is further divided into a first portion receiving cooling air from pressure side passages and a second portion receiving cooling air from suction side passages, allowing independent temperature management for different tip regions.
Solution Approach 2:
The tip plenum acts as an intermediary chamber between the skin core passages and the airfoil tip. It receives cooling air from both pressure and suction side passages, allows thermal mixing and pressure equalization, and then delivers the cooling air to the tip through discharge openings, preventing direct exposure to extreme thermal gradients.
2Reliability
If cooling air flows directly from compressor to airfoil tip, then tip cooling is achieved, but the cooling effectiveness is reduced due to heating from external surfaces
Solution Approach 1:
Cooling air is preliminarily cooled by routing it through the compressor blade passages and tip plenum before it reaches the airfoil tip. The tip plenum allows the cooling air to acclimate and mix thermally before discharge, ensuring maximum cooling effectiveness at the tip region.
Solution Approach 2:
Different regions of the airfoil receive cooling air with different thermal characteristics. The tip plenum's first portion receives cooler air from pressure side passages while the second portion receives air from suction side passages, creating localized cooling zones optimized for their specific thermal environments.
3Temperature
If the tip plenum is fluidly coupled to both pressure and suction side passages, then comprehensive tip cooling is achieved, but thermal isolation is compromised
Solution Approach 1:
The tip plenum is segmented into distinct first and second portions that are spatially separated. The first portion interfaces with pressure side skin core passages while the second portion interfaces with suction side skin core passages, allowing thermal isolation of cooling air streams until they meet in the plenum for beneficial mixing.
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 design ensures that cooling air effectively cools the tip of the airfoil with higher heat transfer coefficients, reducing uncooled areas and improving the overall cooling efficiency of the gas turbine engine components.
Implementation Method 1
a tip plenum located proximate to the tip of the airfoil, the tip plenum being fluidly coupled to the at least one main body cavity
Implementation Method 2
cooling air effectively cools the tip of the airfoil with higher heat transfer coefficients
Implementation Method 3
the at least one main body cavity being located between the pressure side skin core passages and the suction side skin core passages
Data Source
AI summary
A blade for a gas turbine engine, including: an airfoil having a leading edge, a pressure side, a suction side and a trailing edge that extend to a tip of the airfoil; a leading edge cavity located within the airfoil; at least one main body cavity located within the airfoil; pressure side skin core passages located within the airfoil; suction side skin core passages located within the airfoil, the at least one main body cavity being fluidly isolated from the pressure side skin core passages and the suction side skin core passages and the at least one main body cavity being located between the pressure side skin core passages and the suction side skin core passages; a trailing edge feed cavity located within the airfoil; and a tip plenum located proximate to the tip of the airfoil, the tip plenum being fluidly coupled to the at least one main body cavity, wherein the tip plenum is located above the pressure side skin core passages and the trailing edge feed cavity and extends to the trailing edge of the airfoil.