Multiple Core Gas Turbine Engine Variable Cycle Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engines face limitations in reducing spool shaft diameter due to critical speed issues and torque transmission, leading to inefficiencies between fan and core sections, and require costly and time-consuming design and testing for varying power requirements.
Innovation Solution
A gas turbine engine system with multiple engine cores and a control assembly that allows for operational mode switching, decoupling fan and core efficiencies, using a gearbox for torque transmission and multiple engine cores to optimize power output and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If shaft diameter is reduced to decrease engine size, then engine size is reduced, but critical speed issues arise and torque transmission capability decreases
Solution Approach 1:
The engine is divided into multiple independent engine cores (first engine core, second engine core) that can operate independently or together. This segmentation allows the system to achieve desired power output without requiring a single large shaft, thereby maintaining adequate critical speed margins while meeting power requirements.
Solution Approach 2:
Multiple engine cores share common components (intake manifold, exhaust collector, electrical system), allowing the system to achieve multiple power levels (single core operation, dual core operation) without requiring separate complete engine systems. This multi-functionality reduces overall engine size while maintaining reliability through redundant core operation capabilities.
2Device complexity
If fan and core sections are bound to fixed rotational relationship, then mechanical linkage is simplified, but efficiency trade-offs occur between fan and core sections at different operating conditions
Solution Approach 1:
The system enables dynamic operation where engine cores can be selectively activated or deactivated based on power demands. The control assembly dynamically adjusts which cores are active, allowing the fan and core sections to operate at optimal efficiency points independently rather than being constrained to fixed rotational relationships.
Solution Approach 2:
The system changes operational parameters by selectively activating different numbers of engine cores (one core or two cores) to match different power demands. This allows the core section to operate at high efficiency points while the fan operates at appropriate speeds, eliminating the efficiency trade-offs that occur with fixed rotational relationships.
3Device complexity
If single engine core is used, then device complexity is reduced, but flexibility in power output and efficiency across different operating conditions is limited
Solution Approach 1:
The control assembly provides dynamic control over engine core activation, enabling the system to adapt to varying power demands by selectively operating one or both engine cores. This dynamic configuration provides flexibility in power output while maintaining relatively simple device architecture through shared common 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
The system achieves flexible power output and improved efficiency by selectively activating engine cores, reducing trade-offs between fan and core efficiencies and allowing for efficient operation across a wide range of power levels without the need for extensive redesign.
Implementation Method 1
The plurality of engine cores delivers combustion products to the exhaust collector in a tangential orientation to produce an annular exhaust mixing flow
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A gas turbine engine system (10) includes a fan assembly (12), a low pressure compressor (14), a low pressure turbine (16), a plurality of engine cores (30-1 to 30-n) including a first engine core and a second engine core, and a control assembly (36). A primary flowpath (FP) is defined through the fan assembly (12), the low pressure compressor (14), the low pressure turbine (16), and the active engine cores. Each engine core includes a high pressure compressor (40), a combustor (38) downstream from the high pressure compressor (40), and a high pressure turbine (42) downstream from the combustor (38). The control assembly (36) is configured to control operation of the plurality of engine cores (30-1 to 30-n) such that in a first operational mode the first and the second engine cores are active to generate combustion products and in a second operational mode the first engine core is active to generate combustion products while the second engine core is idle.