Offset Core Gas Turbine Engine for Modular Servicing
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Solution Overview
Problem
The inter-relationship of turbine, compressor, and fan sections in traditional gas turbine engines makes servicing complex, as they must be removed as a combined unit, limiting maintenance and mounting options due to the concentric rotation and the risk of disk burst zones interfering with aircraft components like fuel tanks.
Innovation Solution
The gas turbine engine design features a core engine mounted at an offset axis relative to the propulsion unit, allowing the disk burst zone to be angled away from critical areas, enabling separate servicing and more flexible mounting options by using a free turbine and gear reduction to drive the fan at a slower speed, and allowing for modular sizing with multiple core engines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If turbine, compressor, and fan sections are mounted coaxially in a combined unit, then the engine structure is compact and integrated, but servicing becomes complex requiring removal of all sections together
Solution Approach 1:
The engine is divided into separate serviceable modules: the core engine (compressor and turbine sections) can be removed and serviced independently from the fan section. This segmentation allows maintenance personnel to access and repair the core components without having to remove the fan, significantly reducing servicing complexity while maintaining engine integration during operation.
2Device complexity
If the fan and compressor are mounted coaxially with turbines at the rear, then the engine has a traditional compact layout, but disk burst zones can interfere with aircraft components like fuel tanks
Solution Approach 1:
The core engine is offset laterally from the fan axis, creating a three-dimensional configuration where the core engine operates on a parallel axis rather than the same axial line. This dimensional change positions the disk burst zones away from critical aircraft components such as fuel tanks, eliminating the harmful interference while preserving the compact engine layout.
3Length of moving object
If a gear reduction is incorporated to rotate the fan at slower speeds, then the outer diameter of the fan can increase, but the device complexity increases
Solution Approach 1:
A gear reduction mechanism acts as an intermediary between the turbine and the fan, allowing the fan to rotate at a slower speed than the turbine. This intermediary device enables the fan to achieve a larger outer diameter for improved aerodynamic performance while the turbine maintains its high-speed operation, effectively mediating between the conflicting speed and size requirements.
4Adaptability or versatility
If the core engine is offset from the fan axis, then mounting options become more flexible and disk burst zones are redirected, but the engine structure becomes more complex
Solution Approach 1:
The core engine is mounted asymmetrically on an offset axis rather than being centered on the fan axis. This asymmetric configuration redirects the disk burst zones away from critical aircraft components and provides flexible mounting options for different aircraft configurations. The asymmetric design is compensated by structural supports and mounting brackets that maintain overall engine stability and alignment.
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 design simplifies servicing, enables more rearward mounting of the engine under the wing, and allows for modular engine sizing and redundancy, increasing thrust capacity and reducing the risk of damage from disk burst zones.
Implementation Method 1
incorporate a gear reduction such as the fan can rotate at slower speeds than the compressor stage
Data Source
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AI summary
A separate propulsion unit incorporating a free turbine and a fan receives gases from a plurality of core engines. The core engines each include a compressor, a turbine and a combustion section. The core engines in combination pass gases across the free turbine. A method is also disclosed.