Abradable Coating Deposition on Turbomachine Casing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current acoustic coatings for aircraft engines, particularly in new generation turbofan engines with Ultra-High-Bypass-Ratio technology, face challenges in noise reduction due to reduced available areas and shape defects in composite material casings, necessitating innovative noise reduction technologies that maintain engine performance and do not increase specific fuel consumption.
Innovation Solution
A method of in situ deposition of an abradable coating using a filamentary material deposition system to create a three-dimensional scaffolding of channels on turbomachine casings, with a predefined deposition trajectory and adjustable nozzle positions, forming a porous microstructure for effective acoustic wave absorption through visco-thermal dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional composite panels with honeycomb core are used for acoustic coatings, then noise attenuation is achieved, but the available area is reduced and shape defects occur in new generation engines
Solution Approach 1:
The patent applies porous abradable material with controlled porosity (30-70%) deposited directly on the casing surface. This porous structure provides acoustic absorption functionality without requiring thick composite panels, thereby preserving the available area on the casing while achieving effective noise attenuation across a wider frequency range including low frequencies.
Solution Approach 2:
The invention transitions from two-dimensional composite panels to three-dimensional porous structures with controlled pore size and distribution. This dimensional change enables acoustic functionality within a thinner profile, maximizing the available area on the casing while maintaining or improving noise reduction performance.
2Object-affected harmful factors
If traditional composite panels are used, then noise reduction is achieved, but shape defects require additional machining operations
Solution Approach 1:
The abradable coating is deposited preliminary on the casing surface before final assembly, allowing the porous structure to be formed directly in the desired location. This preliminary action eliminates the need for subsequent machining operations to correct shape defects, as the additive process can accommodate surface irregularities and build the correct geometry directly.
Solution Approach 2:
The patent replaces mechanical machining operations with an additive manufacturing process. Instead of removing material through machining to correct shape defects, the porous abradable material is deposited additively, allowing direct formation of the desired geometry and eliminating complex machining steps.
3Object-affected harmful factors
If additive manufacturing is used to create porous structures, then acoustic performance is improved, but manufacturing precision is required for controlled porosity
Solution Approach 1:
The patent controls porosity by adjusting deposition parameters such as filament diameter (0.5-2mm), layer thickness (0.1-1mm), and deposition spacing. These parameter changes enable precise control of the porous structure's pore size and distribution, optimizing acoustic absorption while maintaining manufacturing feasibility through standardized additive processes.
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
The method achieves significant noise reduction across a wider frequency range, including low frequencies, while maintaining engine performance and correcting shape defects, with minimal impact on fuel consumption and other functionalities.
Implementation Method 1
This results in a porous microstructure with regular and ordered porosity which ensures significant absorption of acoustic waves by visco-thermal dissipation within the channels.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for in situ deposition of a coating on a turbomachine casing by additive manufacturing, consisting in depositing a filament (100, 200, 300, 400, 500, 600) of an abradable material on an inner surface of said turbomachine casing (20A, 62) according to a predefined deposition trajectory in order to create a three-dimensional framework of filaments together forming an ordered network (60) of channels, in which method a system for depositing filamentary material (46) is positioned at a determined position and distance from the inner surface of the casing; a first layer of the coating is deposited over 360°; the system for depositing filamentary material is rotated by a first determined angle and the system for depositing filamentary material is positioned at a determined position and distance from the deposited layer; a second layer of the coating is deposited on the first layer of the coating, over a sector of the casing; a movement is made over a determined angular distance corresponding to the first sector that has already been covered, then for the subsequent sectors, until 360° has been covered; and, after having rotated the system for depositing filamentary material by a second determined angle, the process is resumed for the subsequent layers until a desired thickness of coating is obtained.