Integrated Guide Vane Spar for Gas Turbine Weight Reduction
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Solution Overview
Problem
In aircraft gas turbine engines, the integration of a single component that can handle both mechanical loads from bearing frames and aerodynamic loads in the hot gas path between high and low-pressure turbines is challenging due to differing load and temperature requirements, leading to separate struts and inlet guide vanes, which restrict flow and increase weight.
Innovation Solution
A combined inlet guide vane with an internal mechanical load-carrying spar and an aerodynamic shell, where the spar is reinforced with stiffeners that also function as cooling fins, allowing for efficient load transmission and heat dissipation, reducing weight while maintaining structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate struts and inlet guide vanes are used, then each component can be optimized for its specific function, but the flow of working fluid is restricted and engine weight is increased
Solution Approach 1:
The patent combines the strut and inlet guide vane into a single integrated component. The strut portion provides mechanical load transmission from the bearing frame to the engine case, while the guide vane portion directs working fluid flow into the low-pressure turbine inlet. This merging eliminates the need for separate components, reducing overall engine weight while maintaining both mechanical support and aerodynamic functions.
2Temperature
If struts are made hollow to accommodate cooling air flow, then heat dissipation is improved, but mechanical strength is reduced
Solution Approach 1:
The integrated strut-guide vane assembly incorporates cooling air passages specifically in the strut portion where thermal management is critical, while maintaining solid, reinforced construction in the guide vane portion where aerodynamic loading and mechanical strength are paramount. The stiffeners are strategically positioned to provide local reinforcement where needed without compromising overall cooling efficiency.
Solution Approach 2:
The strut portion may utilize heat-resistant materials or thermal barrier coatings to withstand the hot gas path environment while maintaining structural integrity. The combination of material selection and structural design allows the strut to be hollow for cooling while retaining sufficient mechanical strength.
3Strength
If strut mass is increased to handle mechanical loads and thermal loading, then load-bearing capacity is improved, but weight is severely increased
Solution Approach 1:
The integrated assembly segments the load-bearing function (strut portion) from the aerodynamic function (guide vane portion). The strut can be optimized for mechanical strength with appropriate hollow sections and stiffeners, while the guide vane is optimized for aerodynamic performance. This segmentation allows each portion to be weight-optimized for its specific function rather than requiring excessive mass throughout the entire component.
Solution Approach 2:
The stiffeners in the strut portion are designed to provide dynamic reinforcement, distributing mechanical loads and thermal stresses throughout the structure. This allows the strut to achieve high load-bearing capacity with reduced overall mass compared to a solid construction, as the stiffeners provide structural integrity only where and when needed during operation.
4Weight of stationary object
If a combined strut and inlet guide vane is designed, then weight is reduced and flow is improved, but design complexity increases due to diverse load and temperature requirements
Solution Approach 1:
The integrated component is segmented into distinct functional zones: a strut portion for mechanical load transmission, a guide vane portion for aerodynamic flow direction, and intermediate cooling passages. This segmentation allows each zone to be designed and manufactured with appropriate materials and structures optimized for its specific requirements, while the overall assembly benefits from weight reduction compared to separate 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 combined inlet guide vane effectively aligns gas flow, transmits mechanical loads, and dissipates heat, achieving a lightweight and compact design that reduces engine weight without compromising thrust output or structural robustness.
Implementation Method 1
A gap between the spar and the shell may accommodate cooling airflow therethrough to cool the guide vane from the extreme heat loads present in the hot gas flow
Data Source
AI summary
A guide vane for a gas turbine aircraft engine includes an aerodynamic shell for turning a flow of working fluid and an internal spar spaced from the aerodynamic shell by an air gap and reinforced by stiffeners.