Upper Surface Blowing Flow Director for Aircraft Directional Control

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Solution Overview

Problem

Existing upper surface blowing systems for aircraft are limited in directional control during short take-off and landing (STOL) and extreme short take-off and landing (ESTOL) maneuvers due to low dynamic pressure, requiring large control surfaces that increase weight and reduce efficiency.

Innovation Solution

The system employs a flow director and controller to vary the attachment of the exhaust stream to the fuselage, allowing for multi-directional control of aircraft pitch, yaw, and roll by adjusting the degree of attachment, thereby reducing the need for large control surfaces and improving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If control surfaces are made relatively large to counteract reduced effectiveness during STOL maneuvers, then directional control capability is improved, but aircraft weight increases and efficiency decreases

Engineering Contradiction:

Improvedirectional control capabilityVSAvoidaircraft weight

Core Design Contradiction:

Ease of operationVSWeight of moving object

Solution Approach 1:

The exhaust stream from the engine is made to serve multiple functions: it provides thrust for propulsion and simultaneously acts as a control surface by directing it to attach to different parts of the fuselage. This eliminates the need for separate large control surfaces, reducing weight while maintaining directional control capability during STOL maneuvers.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention uses the pneumatic exhaust stream from the engine as a controllable fluid flow to achieve directional control. By varying the attachment point of the exhaust stream to the fuselage, the system generates control forces without mechanical control surfaces, improving ease of operation while reducing weight.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Ease of operation

If control surfaces are made relatively large to counteract reduced effectiveness during STOL maneuvers, then directional control capability is improved, but aerodynamic efficiency decreases

Engineering Contradiction:

Improvedirectional control capabilityVSAvoidaerodynamic efficiency

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The exhaust stream performs dual functions as propulsion and control, eliminating the parasitic drag and energy loss associated with large control surfaces. This reduces aerodynamic inefficiency while maintaining directional control capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention recovers and utilizes the exhaust stream that would otherwise be discarded waste product. By directing this exhaust flow to attach to the fuselage, the system generates control forces without the energy penalty of large control surfaces, improving overall aerodynamic efficiency.

Inventive Principle:

Principle #34Discarding and recovering

3Force

If engines are disposed above the wings for upper surface blowing, then lift generation is improved, but control effectiveness during STOL maneuvers decreases due to low dynamic pressure

Engineering Contradiction:

Improvelift forceVSAvoidcontrol effectiveness

Core Design Contradiction:

ForceVSEase of operation

Solution Approach 1:

The fuselage acts as an intermediary surface between the exhaust stream and the control system. By directing the exhaust stream to attach to different locations on the fuselage, the system generates control forces that complement the lift generation from upper surface blowing, maintaining control effectiveness despite low dynamic pressure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention adds a new dimension to control by utilizing the vertical attachment of exhaust stream to fuselage, rather than relying solely on traditional horizontal control surfaces. This provides additional degrees of freedom for control during STOL maneuvers where dynamic pressure is low.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 approach enables effective maneuvering at low dynamic pressures, reduces aircraft weight and drag, and enhances fuel and aerodynamic efficiency, while also improving survivability and detectability.

Implementation Method 1

the efflux may follow a curvature of the upper surfaces of the wings and the flaps to provide lift

Methodology Applied

Scientific EffectCoanda effect: Coanda Effect

Data Source

PatentUS9889924B2Multi-directional control using upper surface blowing systems

Publication Date: 2018.02.13 THE BOEING CO

AI summary

Multi-directional control using upper surface blowing systems is described herein. One disclosed example method includes a flow director of an aircraft, where the flow director is to cause an exhaust stream of an upper surface blowing system to attach to a fuselage of the aircraft, and a controller to control the flow director to affect one or more of a pitch, a yaw or a roll of the aircraft by varying a degree of the attachment of the exhaust stream to the fuselage.