Turbomachine Sealing Module Deflector Design
Solution Overview
Problem
Current turbomachine designs face issues with thermal protection and gas leaks due to sectorization of the sealing ring, leading to casing overheating, deformation, and reduced turbine performance, as well as inter-sector leaks that compromise the integrity of the casing rail.
Innovation Solution
A sealing module with a deflector extending radially inward upstream of the abradable coating, aligned with the hook's circumferential ends, is introduced to block gas circulation between the wheel and distributor, and inter-sector clearances are optimized with tabs and notches to enhance sealing, ensuring the deflector's circumferential extent matches the ring sectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the sealing ring is segmented into sectors, then the assembly and maintenance become easier, but circumferential gaps between sectors allow hot gases to escape and heat the casing
Solution Approach 1:
A deflector element is introduced as an intermediary component between the ring sectors. This deflector extends radially inward from the outer periphery and positions itself to block the circumferential gaps between adjacent ring sectors, preventing hot gases from escaping through these gaps and heating the casing.
Solution Approach 2:
The deflector is positioned in the radial dimension to block gas flow paths that would otherwise escape circumferentially. By extending radially inward from the outer periphery of the ring sectors, the deflector creates a three-dimensional barrier that intercepts hot gases before they can reach the casing.
2Object-affected harmful factors
If the shim sectors are circumferentially offset relative to ring sectors, then direct gas contact with the casing rail is reduced, but inter-sector leaks at the middle bottom walls of ring hooks still occur
Solution Approach 1:
The sealing system is divided into multiple functional segments: ring sectors with abradable coatings, shim sectors for thermal protection, deflectors for gas flow control, and sealing tabs for inter-sector sealing. Each segment performs a specific function, and their coordinated arrangement creates comprehensive sealing coverage.
Solution Approach 2:
Multiple sealing components are nested within each other: sealing tabs are positioned within grooves of the ring sectors, deflectors extend from the outer periphery inward, and shims are placed between the hooks and the casing rail. This nested arrangement creates layered protection against gas leakage.
3Reliability
If sealing tabs are inserted between ring sectors, then inter-sector sealing is improved, but space constraints prevent mounting tabs at the circumferential gaps between ring sector hooks
Solution Approach 1:
The deflector is positioned upstream of the ring sectors and extends radially inward to block gas flow before it reaches the inter-sector gaps. This preliminary action prevents hot gases from accessing areas where space constraints would prevent the installation of additional sealing components.
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 effectively limits gas leakage, reduces the risk of casing overheating, and extends the lifespan of the casing rail, thereby improving turbomachine performance and reliability.
Implementation Method 1
designed to wear away through friction against external scuffs of the wheel blades, forming a labyrinth seal
Implementation Method 2
Hot gases can thus pass through the circumferential gaps between the ring sector hooks and impact the shim sectors, which will heat the housing rail by conduction
Data Source
Figure 1~2
Figure 3~4
Figure 5~7
AI summary
Turbomachine turbine sealing module, in particular for aircraft, this turbine module extending around an axis and comprising a distributor (12) fixed to a housing (14) and having at least one blade connected to an external platform (12a), the external platform having a spoiler (34) for attachment to the housing (14), the turbine module further comprising a blade wheel (16) rotatably mounted inside the housing (14) and surrounded by a sealing ring (18) attached to this housing, this ring being sectored and having an annular row of ring sectors arranged so that the circumferential end edges of two adjacent sectors are opposite each other,each ring sector comprising a body (20) carrying an abradable coating (22) configured to cooperate with at least one slat (24) carried by the wheel (16) and a hook (32) extending circumferentially while being located upstream of said abradable coating (22) and configured to cooperate with a rail (36) for attaching the housing (14), this hook (32) having a general C-shaped cross-section with its opening oriented axially upstream and intended to receive said rail (36), characterized in that each ring sector further comprises a deflector (60) which is disposed upstream of said coating and which extends radially inwards and upstream relative to the axis so that its radially internal end extends around a downstream end of the external platform (12a) of the distributor.