Gas Turbine Rotor Bore Thermal Conditioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine components, particularly rotor disks, experience undesirable thermal stresses due to temperature gradients between their rims and bores, leading to potential damage from rapid expansion and cooling during varying engine operating conditions.
Innovation Solution
A gas turbine engine equipped with a heat exchanger system that fluidically connects to both a conditioning air source and hot/cool fluid sources, allowing for selective heating and cooling of rotor bore cavities based on engine operating conditions to mitigate thermal gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If hot gas flows through the compressor section during engine idle or power increase, then the rotor rim temperature increases, but the rotor bore and web temperature increases more slowly, creating thermal gradients and undesirable stresses
Solution Approach 1:
The system performs preliminary heating of the rotor bore cavity before the rim experiences rapid temperature increase. A heater positioned in the bore cavity pre-heats the air and rotor bore/web structure, so when hot gas flows through the compressor, the temperature gradient between rim and bore is reduced, preventing thermal stress
Solution Approach 2:
The patent introduces an intermediary heating system that mediates the thermal transfer between the hot gas and the rotor bore. The heater acts as an intermediary device that directly heats the bore cavity air and rotor bore, creating a more uniform temperature distribution and reducing thermal stress
2Temperature
If the rotor rim cools quickly during aircraft descent, then the rotor bore and web remain relatively hot, creating thermal gradients and undesirable stresses
Solution Approach 1:
The system performs preliminary cooling of the rotor bore cavity before the rim experiences rapid cooling during descent. The cooling system pre-cools the air in the bore cavity and the rotor bore/web structure, so when the rim cools quickly, the temperature gradient is minimized, preventing thermal stress
Solution Approach 2:
The patent introduces an intermediary cooling system that mediates the thermal transfer during rapid cooling. The cooling device acts as an intermediary that directly cools the bore cavity air and rotor bore, creating a more uniform temperature distribution during descent and reducing thermal stress
3Temperature
If metal disks expand when heated during engine operation, then the rotor rim expands more quickly than the web and bore, but this creates undesirable stresses
Solution Approach 1:
The system performs preliminary thermal conditioning of the rotor bore cavity to prevent excessive thermal expansion differences. By pre-heating or pre-cooling the bore cavity air and rotor bore/web structure, the system ensures more uniform thermal expansion across the rotor disk, maintaining structural integrity
Solution Approach 2:
The patent introduces an intermediary thermal conditioning system that mediates the thermal expansion process. The heater or cooler acts as an intermediary that directly affects the bore cavity temperature, creating a more uniform expansion pattern and preventing stress-related structural damage
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 effectively reduces thermal stresses on rotor disk components by maintaining temperature uniformity within bore cavities, thereby extending component lifespan and reducing the risk of damage from thermal expansion and contraction.
Implementation Method 1
The heat exchanger is also fluidically connected to a hot fluid source and a cool fluid source for selectively heating and cooling conditioning air flowing to the rotor bore cavity
Implementation Method 2
The heat exchanger is also fluidically connected to a hot fluid source and a cool fluid source for selectively heating and cooling conditioning air flowing to the rotor bore cavity
Implementation Method 3
Because metal disks typically expand when heated, this can result in a situation where disk rims expand more quickly than disk webs and bores
Implementation Method 4
The opposite effect can happen during aircraft descent, where disk rims cool more quickly than disk bores and webs
Data Source
AI summary
A gas turbine engine includes a rotor having at least one rotor bore cavity and a heat exchanger. The heat exchanger is fluidically connected to a conditioning air source and to the rotor bore cavity for flowing air from the conditioning air source to the rotor bore cavity. The heat exchanger is also fluidically connected to a hot fluid source and a cool fluid source for selectively heating and cooling conditioning air flowing to the rotor bore cavity.