Rotating Electric Anti-Torque Fin for Helicopter Tail Boom
Solution Overview
Problem
Traditional anti-torque systems in helicopters are inefficient as they require larger sizes when not providing maximum thrust, especially in conditions like 35-knot sideward flight, due to permanent cant angles that compromise anti-torque performance.
Innovation Solution
An electric distributed anti-torque system with rotatable electric fans mounted on a tail boom, allowing variable cant angles from vertical to horizontal, providing direct anti-torque thrust when needed and lift when not, eliminating the need for a mechanically driven anti-torque fan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a permanent cant angle is provided to the anti-torque thrust vector to aid in aircraft lift, then lift capability is improved, but anti-torque performance deteriorates in conditions like 35-knot sideward flight
Solution Approach 1:
The anti-torque system employs a rotatable fin structure that allows dynamic adjustment of the thrust vector angle. The fin can rotate between a vertical position (providing maximum anti-torque thrust for counteracting main rotor torque) and a canted position (providing both anti-torque and lift). This dynamic reconfiguration enables the system to adapt to varying flight conditions, resolving the contradiction between maintaining optimal anti-torque performance and providing lift capability.
2Force
If the anti-torque system is designed for maximum thrust, then anti-torque capability is improved, but system size increases when not providing maximum thrust
Solution Approach 1:
The system uses a rotatable fin that can change its orientation to optimize thrust direction based on flight conditions. When maximum anti-torque thrust is needed, the fin is positioned vertically to concentrate all thrust in the horizontal direction. When less anti-torque is needed, the fin can be canted to provide both anti-torque and lift, reducing the required system size while maintaining effectiveness.
Solution Approach 2:
The anti-torque system is designed to perform multiple functions: it can provide pure anti-torque thrust when the fin is vertical, and it can provide combined anti-torque and lift when the fin is canted. This multi-functionality allows a single system to replace what would traditionally require separate systems, reducing overall size while maintaining maximum thrust capability when needed.
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
Enables efficient anti-torque thrust and lift generation, optimizing system performance by varying the cant angle dynamically based on flight conditions without the limitations of traditional mechanically driven systems.
Implementation Method 1
producing a thrust vector from an electric anti-torque fan
Implementation Method 2
two or more electric fans rotatably mounted on a tail boom
Data Source
AI summary
An exemplary anti-torque system for a helicopter includes two or more electric fans rotatably mounted on a tail boom, the two or more electric fans rotatable about a longitudinal axis of the tail boom.