Rotor Blade Mapping for Gas Turbine Noise Reduction
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Solution Overview
Problem
Gas turbine engines experience multiple-pure-tone (MPT) noise due to blade geometry variations and flowfield disturbances, leading to passenger discomfort and excessive community noise, which existing assembly methods struggle to minimize effectively.
Innovation Solution
A rotor assembly with a computer-generated blade map based on moment weight and geometric parameters of blades, allowing for precise mapping and positioning of blades to reduce noise and imbalance, using a computer program to determine the optimal blade placement and ordering for a rotatable machine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional fan assembly methods are used with basic blade mapping, then assembly simplicity is maintained, but MPT noise reduction is insufficient
Solution Approach 1:
The patent applies preliminary action by measuring and recording geometric parameters and moment weights of all fan blades before assembly, then using this pre-collected data to generate an optimized blade map that minimizes MPT noise. The computer system processes blade characteristics in advance and determines the optimal sequencing strategy before physical assembly begins, allowing the assembly process itself to simply follow the pre-calculated map without complex real-time adjustments.
2Object-affected harmful factors
If fan blades are resequenced to reduce MPT noise, then noise levels decrease, but assembly time and complexity increase
Solution Approach 1:
The patent replaces complex mechanical trial-and-error assembly methods with a computer-based system that automatically calculates optimal blade sequencing. The computer system receives blade geometric parameters and moment weights, then generates an optimized blade map that minimizes MPT noise. This substitution of computational algorithms for manual assembly planning significantly reduces the time and complexity involved in achieving optimal noise reduction while maintaining precise blade positioning.
3Object-affected harmful factors
If multiple blade parameters are measured and optimized, then noise reduction effectiveness improves, but measurement and processing complexity increases
Solution Approach 1:
The patent applies parameter changes by measuring specific geometric parameters (such as blade angle, chord length, and profile dimensions) and moment weights of each fan blade, then using these quantitative parameters as inputs to a computer system. The system processes these parameters and generates an optimized blade sequencing map that minimizes shockwave variations and MPT noise. This approach transforms physical blade characteristics into measurable parameters that can be systematically optimized through computational algorithms.
Data Source
AI summary
A method and apparatus for assembling a rotatable machine is provided. The machine includes a first set of blades that extend radially outwardly from a rotor assembly and wherein a second set of blades is available for installation on the rotor assembly. The method includes determining at least one of a moment weight of each blade in the first set of blades and a geometric parameter of each blade in the first set of blades, determining at least one of a moment weight of each blade in the second set of blades and a geometric parameter of each blade in the second set of blades, and determining a mapping order of each blade for the rotor assembly using the moment weight and the geometric parameter of each blade in the first set of blades and the moment weight and the geometric parameter of at least one blade in the second set of blades.