Adaptive Multi-Metal Rotor Tip Seals for Turbomachine Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbomachines face inefficiencies due to tip clearance leaks between rotor blades and stationary components, which existing solutions like labyrinth seals and abradable coatings have not adequately addressed.
Innovation Solution
A rotor blade with a tip seal featuring a bimetallic or multi-metallic composition that changes height in response to temperature, reducing the gap between the rotor blade and shroud, and optionally incorporating an elastic material to prevent rubbing, can be additively manufactured for retrofitting or integrated during production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If tip clearance is minimized to reduce core flow leakage, then turbomachine efficiency is improved, but the risk of rubbing between rotor blades and stationary components increases
Solution Approach 1:
The tip seal utilizes temperature-dependent material properties to change its height dynamically. As temperature increases during operation, the seal material expands or softens to reduce tip clearance, thereby reducing core flow leakage while maintaining reliability through controlled material behavior
Solution Approach 2:
The tip seal is constructed from composite materials with different thermal expansion coefficients or temperature-dependent mechanical properties. This allows the seal to maintain structural integrity at operating temperatures while achieving the desired clearance reduction through differential expansion or controlled deformation
2Strength
If rigid seal materials are used to maintain structural integrity, then strength is improved, but wear and rubbing damage increase due to lack of compliance
Solution Approach 1:
The seal material's mechanical properties change with temperature, transitioning from a rigid state at ambient temperature to a more compliant state at operating temperatures. This parameter change allows the seal to maintain strength when not in contact while reducing wear during operation through increased compliance
Solution Approach 2:
The tip seal transitions from a static, rigid structure to a dynamic, adaptive structure that changes its mechanical properties in response to operating conditions. This dynamic behavior allows the seal to optimize both strength and wear resistance throughout the operational cycle
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 solution significantly reduces core flow leakage, enhancing turbomachine efficiency and counteracting centrifugal forces, while minimizing wear and improving operational stability.
Implementation Method 1
A rotor blade with a tip seal featuring a bimetallic or multi-metallic composition that changes height in response to temperature
Implementation Method 2
optionally incorporating an elastic material to prevent rubbing
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A rotor blade for a turbomachine includes a base (82), a tip (84) opposite the base in a spanwise direction, a leading edge (86), and a trailing edge (88) opposite the leading edge in a chordwise direction. A pressure surface (90) extends from the leading edge to the trailing edge, and extends from the base to the tip. A suction surface (92) extends from the leading edge to the trailing edge, and extends from the base to the tip. The tip includes a tip seal (94) additively manufactured to the rotor blade. The tip seal includes a first portion (104) with a first material composition and a second portion (106) with a second material composition different from the first composition.