Ruddevator Vortex Control for Aerial Refueling Boom

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Solution Overview

Problem

Current boom type aerial refueling systems face limitations in fuel transfer efficiency and aerodynamic range, particularly at high speeds and altitudes, due to insufficient aerodynamic control forces and maneuverability, leading to premature disconnects and reduced refueling envelope.

Innovation Solution

The implementation of an advanced aerodynamic control system for the refueling boom, featuring ruddevators with a chine, raked wingtip, sweep angle, and truncated trailing edge, along with actuators for precise control, allows for improved lift generation and control authority, enabling continuous and efficient fuel transfer over a wider range of conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If traditional ruddevators are used for boom control, then the system structure is simple, but the aerodynamic control forces are insufficient at high speeds and altitudes

Engineering Contradiction:
Improveaerodynamic control forcesVSAvoidruddevator structure complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent applies local quality by modifying specific regions of the ruddevator structure. The chine is added at the leading edge region to generate vortices, the wingtip is raked and swept to improve flow attachment, and the trailing edge is truncated to delay separation. These localized geometric modifications enhance aerodynamic forces without requiring a complete redesign of the entire ruddevator structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs curvature principles through the chine geometry and raked wingtip design. The chine creates a curved leading edge that promotes vortex formation, while the raked and swept wingtip introduces curved surfaces that maintain favorable pressure gradients. These curved geometries improve aerodynamic performance by controlling flow separation and enhancing lift generation at high angles of attack.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Adaptability or versatility

If the refueling envelope is extended to high speeds and altitudes, then the operating range is improved, but the aerodynamic control authority becomes insufficient

Engineering Contradiction:
Improverefueling envelope rangeVSAvoidcontrol authority
Core Design Contradiction:
Adaptability or versatilityVSForce

Solution Approach 1:

The patent applies preliminary action by pre-configuring the ruddevator geometry with vortex-generating features (chine, raked wingtip) before flight operations. These geometric features are designed to automatically generate beneficial vortex flows and delay separation under high-speed, high-altitude conditions without requiring real-time adjustment. The truncated trailing edge similarly prepares the flow for delayed separation, ensuring control authority is maintained across the extended refueling envelope.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the ruddevators are modified with chine, raked wingtip, sweep angle, and truncated trailing edge, then the lift generation and control authority are improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvefuel transfer efficiencyVSAvoidruddevator manufacturing
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by modifying specific regions of the ruddevator structure. The chine is added at the leading edge region to generate vortices, the wingtip is raked and swept to improve flow attachment, and the trailing edge is truncated to delay separation. These localized geometric modifications enhance aerodynamic forces without requiring a complete redesign of the entire ruddevator structure.

Inventive Principle:
Principle #3Local quality

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 solution enhances the aerodynamic control forces, increasing the refueling envelope and preventing premature disconnects, allowing for more efficient and continuous fuel transfer, even at high speeds and altitudes, thereby improving the overall performance and safety of aerial refueling operations.

Implementation Method 1

when positioned at a extreme azimuth angle at a transonic airspeed a vortex will form on the raked wing tip producing a lifting force on the ruddevator

Methodology Applied
Scientific EffectVortex: Vortex Ring

Implementation Method 2

Each ruddevator comprises an airfoil configuration that has a leading edge, a raked wing tip, a trailing edge and an inboard or root edge with a shaft securing the ruddevator to the boom

Methodology Applied
Scientific EffectAerofoil: Aerofoil

Data Source

PatentEP2048080B1Enhanced ruddevator for improved air refueling boom flight control
Publication Date: 2016.08.31 THE BOEING CO
  • EP2048080B1 patent drawingFigure 1
  • EP2048080B1 patent drawingFigure 2
  • EP2048080B1 patent drawingFigure 3

AI summary

In-flight fuel transfer from one aircraft to another aircraft or aerial refueling can extend the flight duration of a receiver aircraft and thereby increase its operational range and/or effectiveness by enabling it to fly farther or for longer duration without returning to the ground. Improved aerial fuel transfer is disclosed in connection with a method and system for in flight transfers of fuel from one aircraft to another. Enhanced fuel transfer operations including boom control are disclosed.