Translatable Low-Drag Surface for Gas Turbine Boundary Layer Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Gas turbine engines face significant aerodynamic losses due to drag, particularly at high Mach numbers, which can lead to non-uniform flow and unsteady forces causing vibrations and potential failure, especially under design constraints that restrict traditional aerodynamic design optimizations.

Innovation Solution

A low drag surface design for gas turbine engines featuring a cut-out region with a continuously translatable surface portion that forms a fluidwash surface, reducing skin friction and altering the boundary layer, combined with an actuator system to optimize translation speed and minimize contact with the aerodynamic surface, thereby reducing drag and flow disturbances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional aerodynamic surface design is used, then the surface area is minimized, but aerodynamic losses increase due to skin friction and flow disturbance

Engineering Contradiction:
Improveaerodynamic lossesVSAvoidsurface design complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies a continuously translatable surface portion that moves relative to the fixed aerodynamic surface. This dynamic element allows the surface to actively interact with the fluid flow, reducing skin friction and altering the boundary layer characteristics. The translation mechanism enables the surface to adapt to flow conditions, thereby reducing aerodynamic losses without requiring complete redesign of the overall surface geometry.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical state and motion parameters of the surface by introducing continuous translation. This parameter change transforms the surface from a static boundary to a dynamically moving one, which fundamentally alters the fluid-surface interaction. The motion parameter of the surface portion reduces the relative velocity between the surface and fluid, thereby reducing skin friction drag and aerodynamic losses.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the surface area is reduced to minimize drag, then aerodynamic losses decrease, but non-uniform flow and unsteady forces increase causing vibrations

Engineering Contradiction:
Improveaerodynamic lossesVSAvoidflow uniformity
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The continuously translating surface portion dynamically adjusts the flow characteristics by moving in sync with or against the fluid flow. This dynamic interaction promotes more uniform flow distribution across the surface and stabilizes the boundary layer, reducing unsteady forces and vibrations that would otherwise occur with static reduced-area surfaces.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent converts the potentially harmful effect of surface motion into a beneficial flow-stabilizing mechanism. The translation of the surface portion, which could create additional disturbances, is instead used to actively manage and uniformize the flow, converting what might be a source of unsteadiness into a flow-control mechanism that enhances reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If design constraints restrict traditional aerodynamic optimizations, then manufacturing simplicity is maintained, but aerodynamic losses remain significant

Engineering Contradiction:
Improvesurface manufacturing simplicityVSAvoidaerodynamic losses
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent segments the surface into a fixed aerodynamic surface and a separate continuously translatable surface portion. This segmentation allows the fixed portion to maintain simple, manufacturable geometry while the movable portion provides the aerodynamic optimization. The segmented design enables independent optimization of each component, maintaining ease of manufacture for the bulk structure while adding performance-enhancing motion to a specific segment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The translating surface portion acts as an intermediary between the simple fixed surface and the desired aerodynamic performance. Rather than requiring complete redesign of the entire surface, this intermediary element provides the necessary flow control and drag reduction, bridging the gap between manufacturing simplicity and aerodynamic efficiency.

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 effectively minimizes aerodynamic losses and reduces the momentum deficit in the boundary layer, enhancing the efficiency and stability of gas turbine engines even at high Mach numbers, while preventing ice accumulation through generated heat.

Implementation Method 1

the translatable surface portion reduces skin friction on the low drag surface

Methodology Applied
Scientific EffectSkin friction reduction: Friction

Implementation Method 2

the translatable surface portion alters the boundary layer across the low drag surface

Methodology Applied
Scientific EffectBoundary layer modification: Boundary Layer

Implementation Method 3

preventing ice accumulation through generated heat

Methodology Applied
Scientific EffectViscous heating: Viscous Heating

Data Source

PatentEP3594114B1Low drag surface
Publication Date: 2023.08.02 ROLLS ROYCE PLC
  • EP3594114B1 patent drawingFigure 1
  • EP3594114B1 patent drawingFigure 2
  • EP3594114B1 patent drawingFigure 3

AI summary

A low drag surface is provided for a fluid washed object, the low drag surface comprising an aerodynamic surface comprising a cut-out region, and a continuously translatable surface comprising a surface portion. The surface portion is positioned in the cut-out region such that the aerodynamic surface and the surface portion form a fluidwash surface, and the surface portion is translatable relative to the aerodynamic surface.