Inside-Out Generator in Turbofan Boost Cavity
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Solution Overview
Problem
Current turbofan and turboshaft engines face challenges in efficiently extracting additional electrical power without compromising engine performance, particularly due to limited space and airflow obstruction, and existing solutions do not effectively utilize the boost cavity for power generation.
Innovation Solution
An 'inside-out' electromagnetic generator is integrated within the boost cavity, featuring a rotor portion rotating around a stator portion, allowing for efficient power extraction from the low-pressure turbine spool with minimal impact on engine geometry and airflow, utilizing an 'inside-out' architecture that includes a rotor with poles and a stator with coils to induce electrical currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If electrical power is extracted from the high-pressure engine spool, then electrical power generation is achieved, but the ability to operate the engine properly at low power levels is reduced
Solution Approach 1:
The patent divides the power extraction function into two separate locations: the high-pressure spool and the low-pressure spool. By placing a generator on the low-pressure spool, the system segments the electrical power generation function from the high-pressure spool, allowing independent power extraction from both spools without interfering with each other's operation.
Solution Approach 2:
The low-pressure spool is given a dual function: it continues to drive the fan while also driving an electrical generator. This multi-functionality allows the same component (low-pressure spool) to serve both mechanical propulsion and electrical power generation purposes, resolving the contradiction between power extraction and engine operation.
2Power
If a generator is placed on the low-pressure engine spool, then additional electrical power source is provided, but the generator size becomes larger due to lower rotational speed
Solution Approach 1:
The generator is nested within the existing low-pressure spool assembly and booster cavity structure. The rotor is positioned within the booster cavity, and the stator is mounted on the low-pressure spool, utilizing the existing spatial framework to accommodate the generator components without requiring additional external space.
Solution Approach 2:
The patent transitions from a conventional external generator placement to an integrated internal arrangement by positioning the generator within the booster cavity and around the low-pressure spool. This dimensional reconfiguration utilizes the three-dimensional space efficiently, fitting the generator into the existing structural envelope rather than adding external volume.
3Power
If space is allocated inside the gas turbine engine for additional components, then power extraction capacity is enhanced, but most of the available space is already utilized
Solution Approach 1:
The generator components (rotor and stator) are nested within the existing booster cavity and low-pressure spool assembly. The rotor is positioned within the booster cavity while the stator is mounted on the spool, creating a nested arrangement that maximizes space utilization without requiring additional external volume.
Solution Approach 2:
The booster cavity and low-pressure spool assembly serve multiple functions: they continue to perform their original mechanical functions while also housing the generator components. This multi-functionality allows the same space to serve both mechanical and electrical power generation purposes.
4Area of stationary object
If the boost cavity is used to house the generator, then space utilization is optimized, but the boost section rotates at low speed requiring special generator design
Solution Approach 1:
The patent inverts the conventional generator configuration by placing the rotor (rotating component) on the outside within the booster cavity and the stator (stationary component) on the inside on the spool. This inverted arrangement allows the generator to accommodate the low rotational speed of the boost section while maintaining efficient electromagnetic coupling.
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 configuration enhances power extraction capacity, allows for controlled power management, and optimizes space usage within the engine, providing a supplemental power source without obstructing airflow or reducing engine performance.
Implementation Method 1
The stator and rotor portions are configured to generate electrical power when the rotor portion is rotated about the stator portion by a shaft of the gas turbine engine to induce electrical currents in the coil portions
Data Source
AI summary
An electrical generator for extraction of electrical power from a gas turbine engine includes a rotor portion and a stator portion disposed within a booster cavity of the gas turbine engine. The rotor portion is rotatably supported about the stator portion. The stator portion rigidly is supported within the booster cavity. The rotor portion has a plurality of poles circumferentially arranged opposite the stator portion. The stator portion includes a plurality of coil portions disposed about an outer periphery of the stator portion adjacent to the stator portion. The stator and rotor portions are configured to generate electrical power when the rotor portion is rotated about the stator portion by a shaft of the gas turbine engine to induce electrical currents in the coil portions. The electrical generator extracts electric power from the turbine engine to supplement primary electrical generation sources of the engine.