Turbine Nozzle Guide Vane Cooling via Sectorized Annular Cavity
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Solution Overview
Problem
Conventional turbine nozzle designs face issues with non-uniform temperature distribution due to rapid mixing of cooling air with hot gas, leading to ineffective cooling of inner and outer platforms.
Innovation Solution
A sectorized nozzle design with a closed annular cavity and staggered cooling air orifices reduces air speed, allowing for improved air impact cooling and uniform temperature distribution by directing cooling air to flow closer to the platform faces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If through orifices are formed in the inner and outer platforms to reintroduce cooling air, then the nozzle inlet temperature becomes more uniform circumferentially, but the cooling air penetrates radially a long way and mixes quickly with hot gas, reducing cooling effectiveness
Solution Approach 1:
The invention divides the single orifice function into two separate components: platform orifices for air intake and cavity orifices for air discharge. This segmentation allows the cooling air to be introduced and then redirected along the platform face, preventing deep radial penetration and rapid mixing with hot gas, thereby maintaining cooling effectiveness while achieving temperature uniformity.
Solution Approach 2:
The invention introduces a circumferential annular cavity that redirects cooling air from radial flow to circumferential flow along the platform face. By changing the flow dimension from radial penetration to circumferential movement, the cooling air remains in contact with the platform surface longer without mixing quickly with hot gas, resolving the contradiction between temperature uniformity and cooling effectiveness.
2Speed
If cooling air is introduced at high speed through platform orifices, then cooling air reaches the platform quickly, but it penetrates deeply into the annular passage and mixes with hot gas before providing effective cooling
Solution Approach 1:
The circumferential annular cavity acts as an intermediary structure between the platform orifices and the cooling target. It receives high-speed cooling air and converts it to a controlled flow that moves along the platform face, preventing direct deep penetration into the hot gas region. The cavity mediates the cooling air's journey, maintaining its cooling capability while achieving the cooling objective.
3Productivity
If cooling air flows quickly through the annular passage, then cooling air is delivered efficiently, but it mixes rapidly with hot gas and cannot provide good cooling of the platforms
Solution Approach 1:
The invention creates different flow conditions in different locations: high-speed flow through the orifices for efficient delivery, then controlled circumferential flow along the platform face for effective cooling. The local quality of the flow changes from high-velocity jet to surface-parallel flow, allowing both efficient delivery and effective cooling to be achieved in their respective zones.
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 enhances cooling efficiency and achieves more uniform circumferential temperature distribution within the nozzle, ensuring better platform cooling and reduced temperature non-uniformities.
Implementation Method 1
cooling air feed orifices that are offset tangentially in a staggered configuration relative to the orifices in the platform... enables the air that enters via the orifices in the cavity to cool the platform by air impact
Implementation Method 2
cool the platform by air impact... flows along the faces of the platforms inside the nozzle
Data Source
AI summary
A sectorized nozzle for a turbine engine turbine including an inner sectorized annular platform and an outer sectorized annular platform connected together by radial airfoils, at least one of the platforms including a plurality of orifices for passing air in a neighborhood of its upstream end, the orifices being distributed over the circumference of the platform and opening out at their ends remote from the airfoils into a circumferential annular cavity of the sector of the platform, which cavity is closed by a metal sheet fastened to the platform sector and pierced by orifices for feeding cooling air.