Variable Geometry Vane Width Profile Reduces Tip Vortex Losses
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Solution Overview
Problem
Existing turbomachines suffer from reduced operating efficiency due to flow energy loss as combustion gases pass through clearance spaces between variable geometry vanes and the turbomachine casing, leading to increased tip vortexes and mixing losses.
Innovation Solution
A variable geometry vane design with a pressure surface and suction surface that increases in width at one end, reducing the flow of combustion gases over the end and through the clearance space, and redirects the flow towards the center of the combustion gas path to enhance work extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If variable geometry vanes are used with clearance spaces to facilitate pivoting, then the vanes can adjust cross-sectional area of combustion gases, but flow energy loss increases due to combustion gases flowing over the ends and through the clearance space
Solution Approach 1:
The vane is divided into multiple sections along its span, with each section independently adjustable. This segmentation allows the vane to maintain a tighter fit with the casing while still providing variable geometry functionality, reducing clearance losses while preserving adaptability.
Solution Approach 2:
The invention introduces a spanwise dimension to the vane geometry, creating a three-dimensional control structure. By adjusting the vane angle differently at various spanwise positions, the system can reduce clearance flow losses while maintaining the ability to control combustion gas flow area.
2Ease of operation
If clearance space is provided at ends of variable geometry vanes for pivoting, then the vanes can rotate to adjust flow area, but tip vortexes and mixing loss increase reducing turbine efficiency
Solution Approach 1:
Dividing the vane into spanwise segments allows each section to be adjusted independently, enabling the trailing edge to maintain better alignment with the casing while the leading edge provides the necessary pivoting clearance, thus reducing tip vortex formation.
Solution Approach 2:
Different portions of the vane have different geometric characteristics - the root portion provides pivoting clearance while the tip portion is designed to minimize clearance and reduce tip vortexes. This local differentiation optimizes both pivoting capability and efficiency.
3Ease of operation
If combustion gases flow over the ends of variable geometry vanes, then the vanes can pivot with clearance space, but the amount of combustion gas flow energy imparted on the vanes increases
Solution Approach 1:
By introducing spanwise variation in vane geometry and adjustment capability, the system can direct the majority of combustion gas flow through the optimized mid-section of the vanes, while the end sections maintain minimal clearance for pivoting without significantly impacting the energy transfer to the rotor.
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
This design reduces flow losses, decreases energy imparted on the vanes, and minimizes tip vortexes and mixing losses, thereby increasing the overall efficiency of the turbine engine and reducing fuel consumption.
Implementation Method 1
redirects the flow towards the center of the combustion gas path to increase work extraction in the turbomachine
Implementation Method 2
As the combustion gases impact the variable geometry vanes, at least a portion of the combustion gas flow energy is imparted on the vanes
Implementation Method 3
The flow through the clearance space generates tip vortexes and mixing loss
Implementation Method 4
The flow through the clearance space generates tip vortexes and mixing loss
Data Source
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AI summary
A vane for a turbomachine includes a pressure surface and a suction surface opposite the pressure surface. The pressure surface and the suction surface define a width therebetween. The vane also includes a first end. The first end includes a distal portion, a proximal portion, a pressure surface first portion, and a suction surface first portion. At least one of the pressure surface first portion and the suction surface first portion slope away from the other of the pressure surface first portion and the suction surface first portion such that the width increases from a first end minimum width at the proximal portion to a first end maximum width at the distal portion.