Aerospace Tail Section Yaw Control via Segmented Rudder and Thruster

Solution Overview

Problem

Conventional aircraft tail sections with large fins for yaw control result in significant drag and weight, as they are designed for emergency engine loss scenarios, while requiring smaller yawing moments under normal conditions.

Innovation Solution

A tail section with a movable rudder and an electrically powered thruster, which includes an air intake, acceleration device, and air outlet, works in series to generate yawing moments, allowing the rudder to be sized for normal conditions and the thruster to provide additional moments in emergencies, reducing fin size and drag.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large tail fin is used to provide sufficient yaw control in emergency situations, then the yaw control capability is improved, but the drag and weight increase significantly

Engineering Contradiction:

Improveyaw control capabilityVSAvoiddrag

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The yaw control function is segmented into two independent components: a rudder for normal operating conditions and a thruster for emergency situations. This allows the rudder to be sized appropriately for normal conditions rather than being oversized for emergency conditions, thereby reducing drag during normal flight while maintaining emergency capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An electrically powered thruster is introduced as an intermediary device between the rudder and the aircraft body. The thruster provides additional yawing moment in emergency situations, allowing the rudder to be smaller and reducing overall drag while maintaining sufficient yaw control capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a large tail fin is used to provide sufficient yaw control in emergency situations, then the yaw control capability is improved, but the aircraft weight increases

Engineering Contradiction:

Improveyaw control capabilityVSAvoidaircraft weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The yaw control function is segmented into two independent components: a rudder for normal operating conditions and a thruster for emergency situations. This allows the rudder to be sized appropriately for normal conditions rather than being oversized for emergency conditions, thereby reducing drag during normal flight while maintaining emergency capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces a larger mechanical rudder system with a combination of a smaller rudder and an electrically powered thruster. The thruster uses electrical actuators rather than large mechanical surfaces, reducing weight while providing the necessary additional yawing moment for emergency situations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the rudder is sized for emergency situations, then the yaw control capability is improved, but the drag increases during normal flight

Engineering Contradiction:

Improveemergency yaw controlVSAvoidenergy loss due to drag

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The system dynamically switches between using the rudder for normal conditions and the thruster for emergency conditions based on the operational state. This dynamic approach allows the aircraft to minimize drag during normal flight by using only the necessary control surfaces while maintaining the capability for emergency yaw control when needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

An electrically powered thruster is introduced as an intermediary device between the rudder and the aircraft body. The thruster provides additional yawing moment in emergency situations, allowing the rudder to be smaller and reducing overall drag while maintaining sufficient yaw control capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution enables reduced drag and weight by allowing a smaller fin size while maintaining sufficient yaw control, with the thruster supplementing rudder-generated moments during emergencies and providing additional control under normal conditions.

Implementation Method 1

an electrically powered device for accelerating the air received through the intake, and an air outlet which directs the accelerated air to increase the yawing moment generated by the rudder

Methodology Applied

Scientific EffectThrust generation: Jet

Data Source

PatentUS8960599B2Aerospace vehicle yaw generating tail section

Publication Date: 2015.02.24 ROLLS ROYCE PLC

AI summary

A tail section for an aerospace vehicle is provided. The tail section comprises a rudder which is movable about an axis to generate a yawing moment on the aerospace vehicle. The tail section further comprises a thruster having, in flow series, an air intake, an electrically powered device for accelerating the air received through the intake, and an air outlet which directs the accelerated air to increase the yawing moment generated by the rudder.