Turbomachine Propeller Blade Setting Mechanism for Noise Reduction
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Solution Overview
Problem
The noise generated by turbomachine propeller blades during takeoff, climbing, and landing is exacerbated by the dissymmetry of loads caused by varying incidence angles, leading to increased sound levels due to non-uniform blade loading, which existing technologies fail to adequately address.
Innovation Solution
A device comprising coaxial discs with coupling means that allow for tilting while maintaining a constant coupling distance, enabling active adjustment of blade settings to adapt to non-homogeneous load distributions, thereby reducing noise through heterogeneous blade settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the propeller operates with a non-zero incidence angle during takeoff, climbing, or landing, then the propeller can generate the necessary thrust for these flight phases, but the dissymmetry of loads on the blades increases, causing higher noise levels
Solution Approach 1:
The patent applies local quality by allowing each blade to have a different setting angle optimized for its specific angular position on the propeller disc. Blades at different positions experience different load conditions due to incidence angle, and this invention enables local adjustment of each blade's pitch angle to optimize performance and reduce noise at each location rather than using a uniform setting across all blades.
Solution Approach 2:
The invention implements dynamics by making the blade settings adjustable and adaptable to varying flight conditions. The control system can dynamically modify blade settings based on real-time measurements of load distribution and acoustic emissions, allowing the propeller to optimize its performance characteristics for different operating phases such as takeoff, climbing, or landing.
2Object-generated harmful factors
If the blade settings are made heterogeneous to adapt to non-uniform load distributions, then noise levels are reduced, but the device complexity increases due to the need for multiple adjustment mechanisms
Solution Approach 1:
The patent merges multiple functions into a single integrated control system that simultaneously manages the adjustment of multiple blades. The control system receives inputs from load distribution sensors and acoustic emission sensors, processes this information centrally, and coordinates the adjustment of all blades through a unified control architecture, thereby reducing overall system complexity despite the heterogeneous blade settings.
Solution Approach 2:
The invention implements self-service through feedback control where the system automatically adjusts blade settings based on real-time measurements of load distribution and acoustic emissions. The control system monitors the operational state and autonomously optimizes blade positions without requiring external intervention, allowing the propeller to self-adjust to varying flight conditions and minimize noise generation.
3Manufacturing precision
If the coupling distance between blades and discs is maintained constant during tilting, then the blade rotation is precisely controlled, but the manufacturing precision requirements for the coupling means increase
Solution Approach 1:
The patent applies equipotentiality by designing the coupling means to maintain a constant coupling distance between the blade and the discs during tilting movements. This constraint creates an equipotential condition where the blade rotates along a precise arc, ensuring consistent and accurate blade settings throughout the adjustment range. The coupling mechanism is designed to maintain this constant distance through geometric constraints and precision-machined surfaces.
Data Source
AI summary
A device for setting a turbomachine propeller blade is provided. The setting device includes a first disc and a second disc respectively provided with first and second coupling devices, the first and second discs being coaxial; and a system for tilting at least one of the first and second discs with respect to the other. During a tilting of at least one of the first and second discs with respect to the other, the coupling distance of the at least one blade on the first and second discs remains constant, bringing about the rotation of the at least one blade.