Axially Divided Inner Ring for Variable Vane Sealing
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Solution Overview
Problem
Existing aircraft engine inner ring designs for variable vanes suffer from leakage and thermal cording issues, leading to aerodynamic losses and reduced engine efficiency due to imperfect sealing and thermal expansion.
Innovation Solution
An axially divided inner ring with varying vane mounts, including guide and play mounts, allows for a tighter connection with vanes, minimizing thermal expansion effects and improving guiding, thereby reducing leakage and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the inner ring uses a floating design with play in vane mounts to allow thermal expansion, then thermal cording is reduced, but leakage increases due to imperfect sealing
Solution Approach 1:
The inner ring is divided into multiple segments that can move independently relative to each other, allowing thermal expansion while maintaining sealing. Each segment can expand or contract locally without causing excessive leakage across the entire structure.
Solution Approach 2:
Different regions of the inner ring have different degrees of freedom. Some vane mounts have play to accommodate thermal expansion, while other areas maintain tighter clearance for sealing. This local differentiation allows the structure to simultaneously handle thermal effects and minimize leakage.
2Loss of energy
If the inner ring uses a rigid connection with minimal play to minimize leakage, then sealing improves, but thermal cording increases leading to larger radial gaps
Solution Approach 1:
The inner ring transitions from a completely rigid connection to a dynamic system where segments can move relative to each other in response to thermal loading. This controlled mobility allows the structure to adapt to temperature changes without creating excessive radial gaps or cording.
3Ease of manufacture
If the inner ring segments are bolted together or connected through pins to maintain structural integrity, then manufacturing and assembly improve, but wear increases at connection points
Solution Approach 1:
Traditional mechanical connections like bolts and pins are replaced with a more sophisticated interface that allows for thermal movement while maintaining structural integrity. The connection design eliminates high-stress concentration points that cause wear, improving reliability while remaining manufacturable.
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
Enhances engine efficiency by minimizing leakage and reducing thermal cording, leading to improved sealing and extended component lifetime.
Implementation Method 1
the inner ring can expand freely and move radially and is radially controlled in the rotor cavity through its own thermal surrounding conditions
Implementation Method 2
The inner ring has vane mounts, which are formed with play in the radial direction, so that the variable vanes that are arranged in the vane mounts can move at least in the radial direction
Data Source
AI summary
The invention relates to an axially divided inner ring as well as a variable vane cascade for an aircraft engine. The inner ring and the vane cascade improve the efficiency of the aircraft engine in that differently formed vanes and/or vane mounts are formed respectively in the inner ring or in the vane cascade.