Unducted Fan Vane Root Cover for Cooling and Maintenance
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Solution Overview
Problem
The existing unducted-fan aircraft engines face challenges in simplifying the attachment and cooling of vanes, which complicates maintenance and affects aerodynamics and thermal management.
Innovation Solution
The design features a cylindrical nacelle with radially positioned variable-pitch vane supports and a detachable aerodynamic cover that surrounds the vane root and base, allowing for improved aerodynamics and cooling by integrating air intake and discharge openings, and a stationary flap for enhanced airflow during transient states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the vane supports are positioned inside the nacelle, then the structural integration is improved, but the cooling efficiency and maintenance accessibility deteriorate
Solution Approach 1:
The vane support structure is segmented into two distinct zones: an internal portion inside the nacelle for structural integration and an external base portion outside the nacelle for cooling and maintenance. This segmentation allows each zone to fulfill its specific function optimally while maintaining overall structural coherence.
Solution Approach 2:
The vane supports extend from the internal nacelle region into the external secondary jet flow region, utilizing the spatial dimension radially outward from the nacelle. This dimensional transition enables the supports to access the high-velocity secondary jet for cooling while maintaining structural connection inside the nacelle.
2Strength
If the vane roots are securely attached to the supports, then the mechanical strength is improved, but the ease of replacement deteriorates
Solution Approach 1:
The attachment structure is segmented into the vane root, the support base, and the detachable cover. This segmentation allows the vane to be securely attached during operation while enabling quick detachment for replacement by simply removing the cover, without requiring complex disassembly procedures.
Solution Approach 2:
The detachable cover is extracted as a separate removable component that encapsulates the attachment mechanism. This allows the cover to be removed for maintenance access while the secure attachment mechanism remains in place, providing both strength during operation and ease of repair during maintenance.
3Temperature
If additional cooling components are added to the vane supports, then the cooling efficiency is improved, but the device complexity increases
Solution Approach 1:
The external base and detachable cover structure serves multiple functions simultaneously: it provides structural support for the vane, enables cooling through secondary jet exposure, facilitates maintenance access, and ensures aerodynamic fairness. This multi-functionality eliminates the need for separate dedicated cooling components, reducing overall device complexity.
Solution Approach 2:
The vane support structure utilizes the existing secondary jet flow field to provide self-cooling. The high-velocity secondary jet naturally flows over the external base and cover surfaces, providing passive cooling without requiring additional active cooling systems or components.
4Shape
If the detachable cover is made aerodynamic, then the aerodynamic performance is improved, but the manufacturing complexity increases
Solution Approach 1:
The aerodynamic cover is segmented into modular components that can be manufactured separately and assembled. This segmentation allows each component to be produced using standard manufacturing processes while achieving the required aerodynamic surfaces through precise joining of the segments.
Solution Approach 2:
The detachable cover is designed with inherent flexibility in its attachment system, allowing for slight adjustments and tolerances during assembly. This dynamic assembly approach accommodates manufacturing variations while maintaining the required aerodynamic surface quality, reducing the need for extremely tight manufacturing tolerances.
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 simplifies vane replacement, enhances aerodynamics, and improves cooling efficiency, allowing for direct in-flight vane replacement without removing additional engine components, while optimizing airflow for both nominal and transient operational conditions.
Implementation Method 1
detachable aerodynamic cover that surrounds the vane root and base, allowing for improved aerodynamics
Implementation Method 2
integrating air intake and discharge openings, and a stationary flap for enhanced airflow
Implementation Method 3
a second air flow, also called a secondary jet. Said secondary jet surrounds the nacelle and is propelled by the contra-rotating propellers in order to produce the thrust generated by the engine
Data Source
AI summary
The invention relates to an unducted-fan aircraft engine comprising a generally cylindrical nacelle through which a primary jet flows, the nacelle bearing a fan rotor comprising variable-pitch vanes (33) located radially outside the nacelle in order to be traversed by a secondary jet (31) flowing longitudinally around the nacelle. The rotor comprises a hub bearing variable-pitch vane supports each carrying one vane (33), each vane (33) comprising a blade extending from a root that is used to removably attach same to a base of the associated support (34). Each base (36) is located radially outside the nacelle so that it is in the secondary jet, and each assembly formed by a base (36) and the vane root supported by the base (36) is surrounded and covered by a detachable aerodynamic cover (37).