Variable Vane Transition Duct for Tip Turbine Vectoring
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Solution Overview
Problem
Conventional turbofan engines have a complex, elongated structure due to axial flow, making them difficult to package in certain applications, whereas tip turbine engines with a radial temperature profile offer a more compact design but require a transition solution for vertical installations.
Innovation Solution
A transition duct with variable vanes is introduced to transition the outlet of the tip turbine engine from round to rectangular, allowing for vectoring of exhaust gases, enabling the engine to decelerate, hover, or accelerate by commanding the position of the vanes, particularly suitable for vertical installations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional turbofan engine with axial flow is used, then high efficiency is achieved, but the engine structure becomes elongated and complicated, making packaging difficult
Solution Approach 1:
The patent inverts the conventional axial flow arrangement by using a radial flow tip turbine engine where the turbine is located at the periphery rather than the center. This inversion achieves compact packaging while maintaining high efficiency through the radial temperature profile that places hotter turbine discharge air outward and cooler bypass air inward.
2Length of moving object
If a tip turbine engine with radial temperature profile is used, then engine length is significantly reduced, but the outlet shape is round and requires transition for vertical installations
Solution Approach 1:
The patent introduces a transition duct as an intermediary component between the round tip turbine outlet and the rectangular airframe inlet. This transition duct includes variable area vanes that mediate the flow transformation while enabling thrust vectoring, thus maintaining compact length while achieving installation versatility.
3Device complexity
If fixed exhaust outlets are used, then simple structure is maintained, but aircraft maneuverability including hover and reverse thrust is limited
Solution Approach 1:
The patent implements dynamic exhaust outlets with variable area vanes that can change position during operation. These vanes are adjustable to vector thrust in vertical and horizontal directions, enabling hover, reverse thrust, and improved maneuverability while maintaining a relatively simple overall structure through the use of a single adjustable component per exhaust sector.
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 transition duct enables the tip turbine engine to be easily installed vertically, providing enhanced maneuverability and thrust-to-weight ratio while maintaining a compact length, facilitating aircraft vertical lift capabilities.
Implementation Method 1
The variable vanes are installed to vector the exhaust gases. This allows the aircraft to decelerate, hover or accelerate in the forward direction by commanding the position of the variable vanes.
Data Source
AI summary
A transition duct (112) is provided at the outlet of a turbine engine. The transition duct transitions the outlet of the tip turbine engine (10) from round to rectangular. The transition duct also provides a plurality of variable vanes at the outlet of the transition duct. The transition duct incorporates a perimeter slot (124) providing cooling to the duct outer wall and attached components. The variable vanes (120) are installed to vector the exhaust gases. This allows the aircraft to decelerate, hover or accelerate in the forward direction by commanding the position of the variable vanes. One potential application of the tip turbine engine is for vertical installations in aircraft.