Gas Turbine Bleed Plenum Inlet with Non-Uniform Profile
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aero-acoustic resonance in engine bleed systems or cavities, such as plenums, can lead to damaging fluctuating pressure waves and noise, posing risks to turbomachinery and contributing to aircraft noise emissions.
Innovation Solution
The geometry of the bleed plenum is designed with non-uniform profiles on the leading and trailing edges of the bleed passage inlet, which disrupts the coherence of vortices and shear layer instabilities, preventing acoustic resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional uniform profile is used at the bleed passage inlet, then the structure is simple and easy to manufacture, but aero-acoustic resonance occurs causing damaging pressure waves and noise
Solution Approach 1:
The patent applies local quality by introducing non-uniform profiles (such as serrations or undulations) specifically at the inlet edges of the bleed passage, while the rest of the structure maintains conventional uniform geometry. This localized modification disrupts vortex coherence and prevents aero-acoustic resonance without requiring complete redesign of the entire bleed system, thus maintaining ease of manufacture while eliminating harmful resonance effects.
Solution Approach 2:
The patent employs asymmetry by replacing the symmetric uniform profile at the bleed passage inlet with an asymmetric non-uniform profile featuring variations in edge geometry. This asymmetric design creates irregular vortex shedding patterns that prevent coherent resonance, effectively reducing aero-acoustic harmful factors while maintaining structural simplicity.
2Object-affected harmful factors
If a non-uniform profile is used at the bleed passage inlet, then aero-acoustic resonance is reduced, but the manufacturing complexity increases
Solution Approach 1:
The non-uniform profile is applied locally only at the inlet edges of the bleed passage rather than throughout the entire structure. This localized approach minimizes manufacturing complexity by limiting the modified zones to specific critical areas, reducing the overall device complexity while still achieving resonance reduction.
Solution Approach 2:
The patent utilizes curved or serpentine profile variations at the inlet edges, which can be manufactured using standard forming techniques. These curvature-based non-uniform profiles are simpler to manufacture compared to complex geometric features, thereby reducing device complexity while maintaining effectiveness in preventing aero-acoustic resonance.
3Object-generated harmful factors
If a non-uniform profile is used at the bleed passage inlet, then noise emissions are reduced, but the geometric complexity of the component increases
Solution Approach 1:
The asymmetric non-uniform profile at the inlet creates irregular vortex shedding that disrupts coherent noise-generating flow structures. By introducing controlled geometric variations in the inlet shape, the patent reduces noise emissions from aero-acoustic resonance while managing geometric complexity through targeted rather than comprehensive design modifications.
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
This design effectively reduces or eliminates aero-acoustic resonance, minimizing potential damage to engine components and reducing noise emissions by ensuring that vortices interact in a less coherent manner.
Implementation Method 1
the high speed air entering the bleed passage and/or passing over the entrance to the bleed passage can create unsteady flow phenomena which may induce undesirable aero-acoustic effects in the bleed passage and/or bleed plenum in the form of fluctuating pressure waves due to resonance
Implementation Method 2
the breakup of the shear layer in the bleed passage inlet and an acoustic standing wave (or acoustic response) in the bleed system or cavity
Implementation Method 3
Aero-acoustic resonance of an engine bleed system or other cavity, such as, for example, a plenum, can be dangerous for the rotating turbomachinery as the generated fluctuating pressure waves can lead to engine/component failure
Data Source
AI summary
A gas turbine engine comprises at least one radially extending bleed passage optionally in fluid communication with at least one generally circumferentially extending plenum. The passage has an upstream inlet in fluid communication with a bleed passage and an outlet for releasing air from the plenum. The upstream leading edge of the inlet or the downstream trailing edge of the inlet has a non-uniform profile.