Pressure-Actuated Riblet Microstructures for Adaptive Drag Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing microstructures on aerodynamic surfaces, such as aircraft and submarines, face challenges in efficiently reducing drag and fuel consumption due to their non-actuatable nature, which limits their adaptability to changing environmental conditions like altitude and depth.

Innovation Solution

The development of self-deployable or passively actuatable riblets formed on a sheet with sealed channels made of elastomeric material, which deform in response to pressure differentials, allowing the riblets to adapt and enhance fluid flow characteristics without mechanical actuators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional non-actuatable microstructures are applied to aerodynamic surfaces, then drag reduction is achieved, but adaptability to changing environmental conditions (altitude, depth) is limited

Engineering Contradiction:
Improveadaptability to changing environmental conditionsVSAvoidcomplexity of actuatable mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The microstructures are designed to dynamically change their configuration in response to environmental conditions. The elastomeric material allows the riblets to deform and adjust their shape based on pressure differentials caused by changes in altitude or depth, enabling the surface to adapt to varying flight or operational conditions rather than remaining static.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system utilizes the natural pressure differentials experienced during altitude changes or depth variations to automatically actuate the microstructures. No external power source or control system is needed - the environmental conditions themselves provide the actuation force, allowing the surface to self-adjust to changing conditions.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If actuatable microstructures with mechanical actuators are used, then adaptability is improved, but device complexity and potential failure points increase

Engineering Contradiction:
Improveadaptability to changing environmental conditionsVSAvoidreliability of actuatable mechanism
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system eliminates mechanical actuators by using the environmental pressure differentials themselves to drive the actuation. The elastomeric material responds passively to pressure changes, converting environmental energy directly into structural deformation without requiring motors, sensors, or control systems that could fail.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Traditional mechanical actuation systems (motors, linkages, sensors) are replaced with a passive elastomeric response system. The pressure differential directly deforms the elastomeric material to change the microstructure configuration, substituting a complex mechanical control system with a simple material response to environmental conditions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If fixed microstructures are applied, then manufacturing simplicity is maintained, but drag reduction efficiency under varying conditions deteriorates

Engineering Contradiction:
Improvedrag reduction efficiencyVSAvoidsimplicity of manufacturing process
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The microstructure parameters (shape, height, configuration) are designed to change in response to pressure differential parameters. The elastomeric material's physical properties allow it to deform under pressure, dynamically adjusting the riblet geometry to optimize drag reduction at different altitudes or depths rather than maintaining a fixed configuration.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The use of elastomeric materials combines the benefits of manufacturability with functional adaptability. These materials can be integrated into existing manufacturing processes while providing the desired passive actuation response, merging structural and functional requirements into a single material system.

Inventive Principle:
Principle #40Composite materials

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 effectively reduces drag and fuel consumption by deploying riblets at specific altitudes or depths, maintaining efficiency and durability, and enabling self-cleaning, thus improving the performance and longevity of vehicles.

Implementation Method 1

the elastomeric material is in a deformed position relative to the sealed channels to define microstructures in the form of riblets

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3085970B1Actuatable microstructures and methods of making the same
Publication Date: 2024.07.31 THE BOEING CO
  • EP3085970B1 patent drawingFigure 1
  • EP3085970B1 patent drawingFigure 2~3
  • EP3085970B1 patent drawingFigure 4

AI summary

Actuatable microstructures and methods of making the same are disclosed. An example a sheet includes a first side including an elastomeric material and a second side opposite the first side. The sheet defines sealed channels. In response to a pressure differential across the elastomeric material, the elastomeric material is to be in a deformed position relative to the sealed channels to define microstructures.