Turbomachine Blisk Casing with Abradable Slots and Circumferential Cavity
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Solution Overview
Problem
Current turbomachine casings struggle to balance aerodynamic performance during cruising with the need to reduce noise generated by vortices at the fan blade interface, particularly during take-off and landing, with existing surface modifications not equally contributing to aerodynamic gains.
Innovation Solution
A blade wheel casing with an internal coating of abradable material featuring circumferential slots and a circular cavity, where slots open into the cavity, optimized in parameters such as height, width, spacing, and angle to enhance aerodynamic performance and noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If circumferential grooves are arranged on the internal surface of the casing, then noise from blade-casing interaction is reduced, but aerodynamic gain is limited especially for downstream grooves
Solution Approach 1:
The patent merges multiple independent grooves into a single circumferential cavity that spans the entire circumference of the casing. This unified cavity structure allows all grooves to work together as one integrated system rather than as separate independent elements, enabling the downstream portion of the cavity to contribute equally to aerodynamic gain as the upstream portion.
Solution Approach 2:
The invention transitions from a two-dimensional surface modification (grooves on the surface) to a three-dimensional volumetric structure (circumferential cavity extending into the casing). This dimensional change creates a volume that can interact with the flow field in a more effective manner, allowing the cavity to sample and redirect turbulence from both upstream and downstream regions equally.
2Object-affected harmful factors
If the casing internal surface is modified to reduce turbulence, then noise during take-off and landing is reduced, but aerodynamic performance during cruising may be compromised
Solution Approach 1:
The circumferential cavity is positioned specifically at the downstream location where blade-casing interaction generates turbulence and noise. By concentrating the flow modification function at this critical location rather than modifying the entire casing surface, the invention reduces noise during take-off and landing while minimizing interference with aerodynamic performance during cruising operations.
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 solution improves aerodynamic gain and noise reduction by effectively sampling and recirculating air flow, with the cavity and slots working together to minimize turbulent flow and noise, while maintaining optimal aerodynamic performance.
Implementation Method 1
an internal coating made of an abradable material
Implementation Method 2
These vortices come from a clearance between the fan casing and the radially outer ends of the fan blades, which makes the air flow turbulent at this location
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a casing (10) for a blisk (20) of a turbomachine (1) comprising an internal coating (11) made of an abradable material, and a plurality of circumferential slots (12) arranged in said coating (11) of abradable material, said casing further comprising a circumferential cavity (13) formed in the coating (11) of abradable material, into which cavity the slots (12) open, said slots (12) opening into said cavity (13) and extending between said cavity (13) and the internal surface (15) of the casing (10). The invention also relates to a turbomachine comprising such a casing and a blisk.