Engine Electrical Machine Air Cooling via Shroud Flow Disturbance
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Solution Overview
Problem
Current cooling methods for electrical machines in aircraft turbine engines are complex and require additional oil cooling, which adds weight and complexity to the system.
Innovation Solution
The integration of elements on the shroud and vanes that generate disturbances in the primary stream, enhancing the thermal exchange coefficient and surface area without the need for oil cooling, thereby improving the cooling efficiency of the electrical machine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If air cooling with additional oil cooling is used, then the electrical machine is sufficiently cooled, but the system complexity and weight increase
Solution Approach 1:
The invention extracts and eliminates the oil cooling subsystem from the cooling system, retaining only the air cooling component. This removes the complexity and weight associated with oil cooling while maintaining sufficient cooling performance through optimized air flow disturbance elements
Solution Approach 2:
The primary stream, originally designed solely for mechanical cooling, is enhanced to perform both mechanical cooling and thermal exchange functions simultaneously. The disturbance elements enable the air flow to effectively cool the electrical machine without requiring a separate oil cooling system
2Temperature
If air cooling with additional oil cooling is used, then the electrical machine is sufficiently cooled, but the system weight increases
Solution Approach 1:
The invention extracts and eliminates the oil cooling subsystem from the cooling system, retaining only the air cooling component. This removes the complexity and weight associated with oil cooling while maintaining sufficient cooling performance through optimized air flow disturbance elements
Solution Approach 2:
The primary stream performs the cooling function for the electrical machine through the disturbance elements, making the system self-sufficient without requiring additional oil cooling infrastructure. The existing air flow system serves the dual purpose of mechanical cooling and thermal exchange
3Temperature
If integral shaping of shroud and vanes is used, then cooling is improved, but load loss increases
Solution Approach 1:
Instead of integral shaping that modifies the entire shroud and vane surfaces, the invention applies localized disturbance elements at specific positions. These elements create targeted turbulence where needed for cooling while preserving the aerodynamic quality of the remaining surfaces, thus minimizing load loss
Solution Approach 2:
The invention applies partial action by using discrete disturbance elements rather than comprehensive integral shaping. This provides sufficient cooling through localized turbulence generation without the excessive aerodynamic penalty of modifying the entire surface 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 solution effectively enhances the cooling of the electrical machine using only air from the primary stream, eliminating the need for oil cooling and reducing the overall weight and complexity of the system.
Implementation Method 1
said shroud and/or said vanes comprise elements configured to generate disturbances in the primary stream
Implementation Method 2
the elements generating disturbances in the primary stream increase the exchange coefficient between the latter and the shroud and/or the vanes and thus the thermal exchange capacity
Implementation Method 3
The vortex created renews the cold air in contact with the hot surface to be cooled of the shroud and/or the vanes of the electrical machine
Data Source
AI summary
Disclosed is an aircraft turbine engine (10), comprising a gas generator (12) and a fan (14) arranged upstream from the gas generator (12) and configured to generate a gas inlet stream (F), part of which flows into a duct of the gas generator to form a primary stream (36), the turbine engine (10) comprising an electrical machine that is mounted coaxially downstream from the fan (14) and that comprises a rotor (62a) surrounded by a stator (62b) carried by an annular shroud (64), this shroud (64) being surrounded by a casing (40) of the gas generator that defines, with this shroud (64), a section of the flow duct for the primary stream (36), stationary vanes (42, 68) for straightening this primary stream (36) extending into this path.