Turbomachine Bleed Valve Cylinder Relocation
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Solution Overview
Problem
Existing bypass turboduct engines face challenges in accommodating compact bleed valve mechanisms for LP compressor control due to limited space, which affects aerodynamic flow and requires bulky cylinders with cooling systems, especially in the fire zone.
Innovation Solution
The control cylinder for the bleed valve is positioned in the second chamber of the inter-duct case, allowing for a smaller, lighter design without a cooling system, and is oriented circumferentially for easier installation, with direct connection to the annular component and rotational freedom, eliminating the need for intermediate rods and reducing the system's mass and space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the control cylinder is placed in the first chamber to control the bleed valve, then the mechanism can be compact, but the available space is extremely limited and it is very difficult to accommodate the mechanism without deforming the profile of the inter-duct case, which would affect the aerodynamic flow
Solution Approach 1:
The control cylinder is extracted from the constrained first chamber and relocated to the second chamber, which has more available space. This extraction resolves the contradiction by allowing the mechanism to be accommodated without deforming the inter-duct case profile, thereby maintaining aerodynamic flow while still providing a compact control system.
2Ease of operation
If door systems are used for bleed valves, then they can be synchronized by a circumferential ring, but the various actuator elements are generally divided between the three chambers of the inter-duct case, depending on the space available in each
Solution Approach 1:
The control cylinder and annular component are merged into a single integrated assembly located in the second chamber. This merging reduces device complexity by consolidating actuator elements that were previously distributed across multiple chambers, while the circumferential ring maintains synchronization capability across all bleed valves.
3Reliability
If cylinders with cooling systems are used to actuate the mechanism in proximity to the HP compressor, then the mechanism can function in the fire zone, but the volume of the cylinders increases further
Solution Approach 1:
The control cylinder is extracted from the fire zone (first chamber near HP compressor) and relocated to the second chamber, which is outside the fire zone. This eliminates the need for a cooling system, thereby reducing the cylinder volume while maintaining operational reliability.
4Volume of moving object
If the control cylinder is positioned in the second chamber, then a smaller, lighter design without a cooling system is achieved, but the cylinder must be oriented circumferentially for easier installation
Solution Approach 1:
The cylinder is designed with rotational freedom about a radial axis, allowing it to be installed in the circumferential orientation required for space efficiency while maintaining the full range of motion needed to actuate the annular component. This dynamic capability resolves the contradiction between compact size and installation ease.
Data Source
AI summary
An assembly including an intermediate case of a bypass turbojet engine and of an inter-jet case extending upstream of the intermediate case to separate a primary air jet of the turbojet engine from its bypass air jet, the inter-jet case including, passing through it, a closable duct for diverting part of the primary flow to the bypass flow thereby forming a blow-off valve for the LP compressor, the intermediate case including arms passing across the bypass flow and the inter-jet case in its internal cavity including a first chamber situated upstream of the arms and a second chamber situated level with the arms, the duct being open or closed off by an annular component capable of axial movement set in motion by an arm that can rotate about a fixed pivot under action of a control cylinder, the cylinder being positioned in the second chamber.