Aircraft Turbomachine Fan Blade with Cellular Inserts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft turbomachine fan or propeller blades face a challenge in balancing aerodynamic performance and structural integrity due to increased dimensions and weight, which can compromise mechanical strength and noise reduction, especially when using thicker blades to enhance natural frequency and reduce noise.
Innovation Solution
The development of a fan or propeller blade made from composite materials with a fibrous reinforcement structure, featuring a spar with longitudinal stiffeners and cellular inserts, which provides both reduced mass and enhanced mechanical resistance through a polymerized resin embedding, ensuring effective force transmission and stress distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the thickness of the blade walls is significantly increased to enhance natural frequency and reduce noise, then the mechanical strength and natural modes of the blade are improved, but the weight of the blade and the size of the turbomachine considerably increase
Solution Approach 1:
The blade structure transitions from uniform thickness to variable thickness distribution, with thicker sections at the root for strength and thinner sections toward the tip for weight reduction. The hollow central part allows localized material placement where structurally necessary.
Solution Approach 2:
The blade employs composite construction combining solid composite material at the root and spar with cellular material (foam) in the central hollow section, achieving both strength and weight reduction through material optimization.
2Weight of moving object
If the blade is made hollow with lighter material in the central part to optimize total mass, then the weight of the blade is reduced, but the structural rigidity during extreme stress is compromised
Solution Approach 1:
The blade is segmented into distinct functional zones: a solid root and spar for structural integrity, a hollow central section with cellular material for weight reduction, and a skin for aerodynamic function. This segmentation allows each zone to optimize its specific function.
Solution Approach 2:
The cellular material in the hollow section provides a balance between weight reduction and maintaining sufficient rigidity, changing the density parameter from solid to porous while preserving essential mechanical properties.
3Productivity
If the outer surface of the blade works mechanically more than the central part, then the aerodynamic performance is optimized, but the central part lacks structural rigidity under extreme stress
Solution Approach 1:
Different parts of the blade are assigned different material properties and structural characteristics: the skin and root use solid composite material for aerodynamic and structural functions, while the central hollow section uses cellular material primarily for weight reduction, creating localized functional optimization.
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 results in a blade with reduced overall mass and improved mechanical resistance to shocks and impacts, such as bird ingestion, while maintaining aerodynamic performance and structural integrity.
Implementation Method 1
the spar and the skin being embedded in a polymerized resin
Data Source
Figure 1~2
Figure 3A~3B
Figure 4
AI summary
Fan or propeller vane (1) for an aircraft turbomachine, the vane being made from a composite material and comprising a blade (2) and a base (3), the base being formed by a longitudinal end (41) of a spar (4) which is formed by a fibrous reinforcement formed from threads woven in three dimensions and a portion (42) of which extends inside the blade (2), the blade (2) having an aerodynamic profile which is defined by a skin (5) which is formed by woven threads and which surrounds the portion of the spar, the spar (4) and the skin (5) being embedded in a polymerised resin, characterised in that the portion (42) of the spar comprises projecting longitudinal stiffening members (6) which together delimit spaces (8) for receiving longitudinal inserts (7) which are formed from a honeycomb material.