Compact Variable Bleed Valve Assemblies for Turbine Engines
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Solution Overview
Problem
Turbine engines face challenges in achieving compact and effective variable bleed valve (VBV) assemblies that maintain aerodynamic performance and efficiency while adhering to stringent engine packaging constraints.
Innovation Solution
The design of VBV assemblies is optimized by establishing a relationship between the axial length of the VBV assembly, the bleed cavity area, and the exit flow angle, which allows for the creation of axially compact VBV assemblies with minimal bleed cavity area and effective actuation mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the axial length of VBV assembly is reduced to meet packaging constraints, then the compactness is improved, but the aerodynamic performance may deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the relationship between axial length, bleed cavity area, and exit flow angle. Specifically, it establishes that the product of axial length and bleed cavity area should be within a specific range (0.001-0.01 m³), and the exit flow angle should be optimized to maintain aerodynamic performance while reducing axial length to meet packaging constraints.
Solution Approach 2:
The patent transitions from one-dimensional axial length optimization to multi-dimensional optimization by considering the interaction between axial length, bleed cavity area, and exit flow angle. This dimensional approach allows achieving compactness in the axial direction while compensating through optimized area and angle parameters to maintain aerodynamic performance.
2Length of moving object
If the bleed cavity area is minimized to reduce axial length, then the compactness is improved, but the flow control effectiveness may worsen
Solution Approach 1:
The patent changes the parameters by establishing an optimized relationship where the product of axial length and bleed cavity area remains within a specific range (0.001-0.01 m³). This ensures that minimizing bleed cavity area for compactness does not excessively compromise flow control effectiveness, as the axial length can be adjusted to compensate.
Solution Approach 2:
The patent introduces dynamic optimization by allowing the VBV door to move between fully closed and fully open positions, with the ability to operate at intermediate positions. This dynamic actuation mechanism maintains flow control effectiveness even with minimized bleed cavity area, as the valve can precisely modulate flow according to operating conditions.
3Reliability
If the exit flow angle is optimized to improve aerodynamic performance, then the efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent optimizes the exit flow angle as a key parameter to improve aerodynamic efficiency. By establishing the relationship between exit flow angle, axial length, and bleed cavity area, the patent achieves enhanced aerodynamic performance through parameter optimization rather than through complex structural modifications.
Solution Approach 2:
The patent makes the VBV assembly multi-functional by integrating flow control, aerodynamic optimization, and compactness achievement into a single integrated structure. The optimized exit flow angle serves multiple purposes: improving aerodynamic efficiency, controlling flow distribution, and enabling compact packaging, thereby reducing the need for additional separate components.
Data Source
AI summary
Compact bleed valve assemblies are disclosed. An example turbine engine comprises a rotor blade having an axial chord (C) measured at a tip of the rotor blade, and a variable bleed valve (VBV) including a VBV port defining a bleed flowpath and an exit angle (βexit) for bleed air exiting the VBV port, the VBV port including a forward entrance edge and an aft exit edge and a first length (LA) therebetween, and a VBV door corresponding to the VBV port, the VBV door to generate a bleed cavity having a bleed cavity area (BA) in the VBV port when the VBV is in a closed position, the VBV door to move between an open position and the closed position at a rotation angle (Δθ), the VBV door to extend a distance (LAact) beyond the first length (LA), whereinLA+LAactC-2*(BVIP+0.15)-1.35≤-0.8,and whereinBVIP=0.15*BAC2+0.85*Δθ+βexit2π.