Integrally Bladed Rotor Blade Off Testing Mechanism
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Solution Overview
Problem
Current blade off testing methods for gas turbine engines lack consistency and accuracy in liberating rotor blades, as regulatory requirements vary and existing techniques may not ensure complete blade liberation, leading to potential uncontained engine failures.
Innovation Solution
An integrally bladed rotor configuration with a central passage and lateral cavities, equipped with a mechanism for facilitating blade liberation, such as a heating element or explosive material, to ensure consistent and accurate blade liberation during testing, aligning with various regulatory standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If explosive liberation or thermal degradation of adhesive is used to liberate rotor blades, then blade liberation can be achieved, but the consistency and accuracy of blade liberation cannot be ensured due to varying regulatory requirements and potential incomplete liberation
Solution Approach 1:
The hub is segmented into multiple functional zones including a central passage, first lateral cavity, and second lateral cavity. These segmented structures allow for controlled distribution of liberation mechanisms at specific locations to ensure consistent and accurate blade liberation according to different regulatory requirements.
Solution Approach 2:
The patent employs parameter changes by using a heating element to thermally degrade adhesive at controlled temperatures, or using explosive materials with controlled detonation parameters. This allows precise control over the liberation process to achieve complete and consistent blade separation while meeting various regulatory specifications.
2Adaptability or versatility
If a mechanism is disposed in the central passage to facilitate blade liberation, then blade off testing can be performed, but the hub structure becomes more complex
Solution Approach 1:
The central passage and lateral cavities serve multiple functions: they house liberation mechanisms (explosive or thermal), control adhesive distribution, and facilitate blade liberation. This multi-functionality reduces the need for separate dedicated structures, thereby managing complexity while enhancing testing capability.
Solution Approach 2:
The liberation mechanisms are nested within the hub structure's central passage and lateral cavities. The heating element or explosive material is contained within the central passage, while the lateral cavities provide additional containment and control zones, creating a nested arrangement that integrates testing functionality into the existing hub geometry.
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
The proposed solution ensures consistent and accurate blade liberation, likely meeting a broader range of regulatory requirements by uniformly weakening the rotor blade attachment, thereby ensuring the engine's safety performance certification.
Implementation Method 1
a mechanism for facilitating liberation of the test blade, wherein the mechanism is disposed in the central passage
Implementation Method 2
thermal degradation of adhesive disposed in slots cut in a rotor blade
Implementation Method 3
an explosive material
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An integrally bladed rotor (IBR) (32) for a gas turbine engine (20) and method is provided. The IBR (32) is configured for use in blade (34) off testing and includes a hub (36), a plurality of rotor blades (34), a central passage (60), and first and second lateral cavities (68, 72). The hub (36) has forward and aft ends and a circumferentially extending exterior surface (38). The central passage (60) is disposed in the hub (36) radially below a test rotor blade (34), extending along a path between an inlet (62) at or forward of the test blade (34) leading edge (46) and an outlet (64) at or aft of the test blade (34) trailing edge (48). The first and second lateral cavities (68, 72) are disposed in the hub (36), extending generally parallel to the central passage (60) path, on opposite circumferential sides. A mechanism (76) is disposed in the central passage (60) for facilitating liberation of the test blade (34) from the IBR (32) during test operation conditions.