Flexible Airfoil Trailing Edge for Laminar Flow Shape Control

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Solution Overview

Problem

Existing aerodynamic profiles, such as aircraft wings, face challenges with invariable rigid shapes that require additional mechanical elements for high-lift functionality, leading to increased weight and disruptions in laminar boundary layer flow.

Innovation Solution

An aerodynamic profile body with flexible cover layers connected by a flexible solid-state hinge and actuators inside, allowing selective cross-sectional changes aligned parallel to the flow direction, reducing tensile and compressive loads and maintaining laminar flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If rigid shapes with additional mechanical elements (high-lift devices) are used to achieve shape adaptability, then the aerodynamic properties can be adjusted for different flight phases, but the weight of the structure increases significantly

Engineering Contradiction:

Improveaerodynamic shape adaptabilityVSAvoidwing structure weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent replaces traditional mechanical high-lift devices (flaps, ailerons) with a flexible membrane system that can be deformed by internal pressure control. This substitution eliminates complex mechanical linkages, hinges, and actuation mechanisms while achieving the same aerodynamic shape-changing function through pneumatic or elastic deformation of the membrane structure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention employs flexible membrane structures as the primary load-bearing and aerodynamic surface. These thin film structures can be deformed into different configurations to achieve high-lift and cruise configurations without requiring rigid mechanical components, thereby reducing overall structure weight while maintaining adaptability.

Inventive Principle:

Principle #30Flexible shells and thin films

2Adaptability or versatility

If mechanical high-lift devices are extended to change wing cross-sectional area, then high-lift functionality is achieved, but disturbances are created in the airfoil's flow surface that disrupt laminar boundary layer flow

Engineering Contradiction:

Improvehigh-lift functionalityVSAvoidflow surface disturbances

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The flexible membrane system provides a continuous, smooth surface that can be deformed into different aerodynamic shapes without creating discontinuities or disturbances. The membrane's ability to conform smoothly to the desired shape ensures uninterrupted laminar flow, eliminating the flow disruptions caused by rigid mechanical devices and their attachment points.

Inventive Principle:

Principle #30Flexible shells and thin films

3Shape

If the cross-sectional shape of the airfoil is modified using flexible surface layers with actuators, then the basic shape of the wing can actually change, but tensile and compressive loads increase across the span

Engineering Contradiction:

Improveairfoil cross-sectional shapeVSAvoidtensile and compressive loads

Core Design Contradiction:

ShapeVSStress or pressure

Solution Approach 1:

The patent utilizes changes in internal pressure parameters to deform the flexible membrane structure into different cross-sectional shapes. By controlling the pressure differential across the membrane, the airfoil can transition between configurations (e.g., high-lift with higher camber, cruise with lower camber) without requiring mechanical force application, thereby reducing structural loads.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4707166A1Aerodynamic profiled body and flying object for same

Publication Date: 2026.03.11 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V

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AI summary

The invention relates to an aerodynamic profile body with an outer flow surface for flow by a fluid, wherein the aerodynamic profile body comprises: - a first cover layer and a second cover layer, which form at least a part of the outer flow surface and are designed to be flexible in an end section of the aerodynamic profile body, - a connection arrangement which flexibly connects the first cover layer to the second cover layer of the profile body in the end section, and - an actuator device with at least one actuator provided in an interior of the aerodynamic profile body, which interacts with at least one of the cover layers in the flexible end section in such a way that the cross-section of the aerodynamic profile body in the flexible end section can be changed by the at least one actuator, characterized in thatthat - the outer flow surface of at least one of the cover layers in the flexible end section has, at least section by section, a surface profile extending parallel to the flow direction.