Gas Turbine Exhaust Nozzle Cam Roller Thrust Vectoring
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Solution Overview
Problem
Existing gas turbine engine exhaust nozzles face limitations in efficiently varying the thrust vectoring and reducing drag, particularly in achieving optimal thrust production and minimizing weight through conventional cam and roller mechanisms.
Innovation Solution
The exhaust nozzle employs a concave cam with a varying contact angle to actuate radial movement of a follower roller, forming a four-bar linkage with convergent and divergent petals, allowing for adjustable petal angles and reduced radial loads, thereby optimizing thrust vectoring and weight reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional cam and roller mechanisms are used to actuate convergent petals, then the exhaust nozzle can vary thrust vectoring, but the radial loads increase and weight increases
Solution Approach 1:
The patent employs a concave cam surface with a radius of curvature that creates a varying contact angle with the follower roller. This curved geometry transforms the force transmission path, allowing the mechanism to accommodate radial movement of the follower roller while maintaining optimal contact angles that reduce radial loads on the convergent petals, thereby reducing overall nozzle weight
2Adaptability or versatility
If conventional cam and roller mechanisms are used to actuate convergent petals, then the exhaust nozzle can vary thrust vectoring, but the radial loads increase
Solution Approach 1:
The concave cam surface geometry with specific radius of curvature creates a varying contact angle that optimizes force transmission. As the cam acts on the follower roller, the curved surface ensures that the contact angle varies to maintain favorable force vectors, minimizing radial load components on the convergent petals while still achieving effective thrust vectoring control
Solution Approach 2:
The patent changes the geometric parameters of the cam mechanism, specifically using a concave cam surface with a defined radius of curvature relationship to the follower roller radius. This parameter optimization allows the contact angle to vary during operation, transforming the force characteristics to reduce radial loads while maintaining thrust vectoring effectiveness
3Weight of moving object
If the cam is positioned to minimize radial loads, then weight is reduced, but the contact angle becomes suboptimal affecting force transmission
Solution Approach 1:
The concave cam surface creates a dynamic contact angle that varies as the cam actuates the follower roller. This curvature ensures that the contact angle is never too small, maintaining optimal force transmission efficiency throughout the range of motion while still achieving weight reduction through minimized radial loads
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 configuration enhances thrust vectoring control, reduces weight by minimizing radial loads, and allows for efficient adjustment of petal angles, improving the overall performance and efficiency of the gas turbine engine.
Implementation Method 1
a cam defining a working surface configured to engage the follower roller to react a force from the petal; wherein the cam is movable along a travel in an axial direction to actuate radial movement of the follower roller to pivot the convergent petal
Implementation Method 2
the cam defines a concave working surface such that a contact angle between the follower roller and the cam varies along the travel to thereby vary a radial component of the force reacted by the cam
Implementation Method 3
forming a four-bar linkage with convergent and divergent petals
Data Source
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AI summary
There is disclosed an exhaust nozzle 20 for a gas turbine engine 10, the exhaust nozzle 20 comprising a frame 30 extending along a longitudinal axis 50. The exhaust nozzle 20 comprises a convergent petal 32 pivotably attached at a convergent pivot point 36 to the frame 30 and extending axially downstream and radially inward from the frame 30, a follower roller 42 fixed to the convergent petal 32 on a radially outer side of the convergent petal 32, and a cam 46 defining a working surface 48 configured to engage the follower roller 42 to react a force from the convergent petal 32. The cam 46 is movable along a travel in an axial direction to actuate radial movement of the follower roller 42 to pivot the convergent petal 32. The cam 46 defines a concave working surface 48 such that a contact angle between the follower roller 42 and the cam 46 varies along the travel to thereby vary a radial component of the force reacted by the cam 46.