Rotorcraft Coanda Anti-Torque Air System for Yaw Control

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Solution Overview

Problem

Existing rotorcraft anti-torque systems face inefficiencies and room for improvement in terms of control and operational complexity.

Innovation Solution

The rotorcraft assembly incorporates a fuselage, tail structure, and a Coanda effect anti-torque system with tail rotors and electric motors, allowing for efficient anti-torque and yaw control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a Coanda effect anti-torque system is used, then anti-torque control efficiency is improved, but device complexity increases

Engineering Contradiction:

Improveanti-torque control efficiencyVSAvoiddevice complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent employs a Coanda effect-based pneumatic anti-torque system that uses compressed air flow through ducts and nozzles to generate anti-torque force, replacing traditional mechanical anti-torque mechanisms. This pneumatic approach improves control efficiency while managing system complexity through standardized pneumatic components.

Inventive Principle:

Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent replaces traditional mechanical anti-torque systems (such as tail rotors or friction-based mechanisms) with a Coanda effect-based pneumatic system. The compressed air flow adhering to the duct surface creates a cushion of air that prevents the rotor from contacting the duct, thereby eliminating mechanical contact and reducing mechanical complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If tail rotors are used for yaw control, then yaw control precision is improved, but device complexity increases

Engineering Contradiction:

Improveyaw control precisionVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical tail rotors with an electrically-driven rotor system. Electric motors provide precise control of rotor speed and direction, enabling accurate yaw control without the mechanical complexity of traditional linkage systems. The electric motor allows for independent control of rotor rotation, improving precision while reducing mechanical wear and complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 provides enhanced control and reduced operational complexity by utilizing the Coanda effect for anti-torque and electric motors for precise yaw control.

Implementation Method 1

The air system includes an air flowpath. The air flowpath passes from the fuselage into the tail boom and extends longitudinally within the tail boom towards the distal end

Methodology Applied

Scientific EffectCoanda effect: Coanda Effect

Data Source

PatentUS20250289567A1Rotorcraft with Anti-torque air system and tail rotor(s)

Publication Date: 2025.09.18 PRATT & WHITNEY CANADA CORP

AI summary

An assembly is provided for a rotorcraft. This rotorcraft assembly includes a fuselage, a tail structure, an air system and a plurality of tail rotors. The tail structure is configured as or otherwise includes a tail boom. The tail boom projects longitudinally along a centerline out from the fuselage to a distal end. The air system includes an air flowpath. The air flowpath passes from the fuselage into the tail boom and extends longitudinally within the tail boom towards the distal end. The tail rotors are connected to the tail structure at the distal end.