Offset Gas Turbine Engine Design for Compact Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas turbine engines have limitations in reducing overall length due to the parallel alignment of fan, compressor, and turbine rotors, which restricts compact design and efficiency.
Innovation Solution
The engine design features offset core engine cores along a non-parallel axis to the fan axis, with dual gas generators and a fan drive turbine driven by combustion products, allowing for a more compact configuration and efficient air delivery through a bypass ratio greater than or equal to 5.0.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the fan, compressor rotors and turbine rotors all rotate about a common axis, then the engine structure is simple and easy to manufacture, but the overall length of the engine cannot be reduced
Solution Approach 1:
The patent transitions from a conventional single-axis configuration to a multi-axis configuration where the fan rotates about a first axis and the gas generator rotors rotate about a second axis that is offset and non-parallel to the first axis. This dimensional change in the rotational axis arrangement enables compact engine packaging while maintaining functional performance.
Solution Approach 2:
The patent divides the engine into separate functional modules with independent rotational axes: the fan module rotating about the first axis and the gas generator module with compressors and turbines rotating about the second axis. This segmentation allows each module to be optimized independently and packaged more efficiently in three-dimensional space.
2Length of moving object
If the core engine is offset along a non-parallel axis to reduce overall length, then the engine becomes more compact, but the alignment and power transmission between components becomes more complex
Solution Approach 1:
The patent introduces a power transmission system as an intermediary mechanism between the gas generator rotors on the second axis and the fan on the first axis. This intermediary system facilitates efficient power transfer while accommodating the offset and non-parallel axis arrangement, simplifying the manufacturing and assembly process despite the complex 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
This design reduces the overall length of the engine while maintaining efficiency by utilizing offset core engines and a bypass ratio that enhances propulsion, enabling effective air delivery and power transmission.
Implementation Method 1
a fan drive turbine driven by products of combustion which have passed downstream over the gas generator turbines, to drive the fan
Implementation Method 2
Compressed air is passed into a combustor where it is mixed with fuel and ignited. Products of this combustion pass downstream across turbine rotors driving them to rotate.
Data Source
AI summary
A gas turbine engine comprises a fan on an engine central axis. Plural gas generators are downstream of the fan, each along a respective central axis, mutually offset, and offset from the engine central axis. A fan drive turbine is on the engine central axis, downstream of the dual gas generators, and driven by output from the dual gas generators, to drive the fan.