Hollow Chevron Ring for Gas Turbine Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine exhaust systems face challenges in reducing acoustic noise, particularly in low and moderate bypass ratio engines used in subsonic civil transports, where noise restrictions are increasingly stringent.
Innovation Solution
The implementation of a chevron ring in the exhaust nozzle system, which includes an attachment ring and a chevron extending downstream with a trailing edge portion, defining a hollow portion between the attachment ring and the trailing edge portion. This design reduces noise by altering the surface area and thickness of the nozzle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a solid chevron structure is used in the exhaust nozzle, then noise reduction capability is improved, but weight and material usage increase
Solution Approach 1:
The chevron ring incorporates a hollow portion that creates a porous or cavity-containing structure. This hollow portion reduces the weight and material usage of the chevron ring while maintaining its noise reduction functionality. The hollow structure allows the chevron to achieve acoustic attenuation without requiring a completely solid construction, thus resolving the contradiction between noise reduction effectiveness and weight reduction.
2Object-affected harmful factors
If a solid chevron structure is used in the exhaust nozzle, then noise reduction capability is improved, but manufacturing complexity and material consumption increase
Solution Approach 1:
The hollow portion within the chevron ring reduces material consumption while preserving the noise reduction capability. By strategically placing a hollow cavity within the chevron structure, the design achieves acoustic attenuation through the chevron geometry itself rather than requiring substantial material volume, thus reducing overall material consumption.
Solution Approach 2:
The invention extracts or removes material from the chevron structure to create the hollow portion. This extraction of unnecessary material reduces both weight and material consumption while maintaining the essential noise reduction function of the chevron, as the acoustic attenuation is achieved through the chevron's geometric shape and flow interaction rather than material density.
3Weight of moving object
If the hollow portion is completely open, then weight is reduced, but structural strength and durability decrease
Solution Approach 1:
The hollow portion is enclosed by a cover skin that forms a thin-walled structure. This cover skin maintains the structural integrity and strength of the chevron ring while allowing the hollow portion to reduce weight. The thin film or shell structure provides the necessary mechanical strength to withstand operational conditions while preserving the weight benefits of the hollow configuration.
Solution Approach 2:
The hollow portion is nested within the chevron ring structure, with the cover skin forming an inner cavity. This nested configuration allows the hollow space to reduce weight while the outer chevron structure and cover skin maintain structural strength, creating a multi-layered structure where each layer serves a specific function.
Data Source
AI summary
A chevron ring is disclosed. In various embodiments, the chevron ring includes an attachment ring; and a chevron, the chevron connected to and extending downstream of the attachment ring and having a trailing edge portion, the chevron defining a hollow portion between the attachment ring and the trailing edge portion.