Composite ALFC Panel With Integrated Plenums for Drag Reduction
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Solution Overview
Problem
Existing active laminar flow control (ALFC) systems for aircraft are difficult to commercially implement due to various deficiencies, necessitating an improved system and manufacturing method for promoting laminar flow over aerodynamic surfaces.
Innovation Solution
An ALFC assembly and manufacturing method involving a suction system fluidly coupled with plenums, integrated into a nacelle for an aircraft propulsion system, utilizing a panel configured from fiber-reinforced composite material with corrugated structures and varying thicknesses to enhance airflow management and reduce drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional ALFC systems are implemented, then laminar flow control is achieved, but manufacturing complexity and commercial feasibility deteriorate
Solution Approach 1:
The patent merges the ALFC system components directly into the nacelle structure itself. The suction ports are integrated into the nacelle skin, and the plenum chambers are formed as cavities within the nacelle structure, eliminating the need for separate housings and reducing assembly complexity. This integration approach maintains laminar flow control effectiveness while significantly improving manufacturability and commercial feasibility.
Solution Approach 2:
The nacelle structure serves multiple functions: it provides aerodynamic shaping, houses the propulsion system, and simultaneously acts as the ALFC system housing with integrated suction ports and plenum chambers. This multi-functionality reduces the total number of components and simplifies manufacturing, directly addressing the commercial implementation challenges.
2Object-generated harmful factors
If ALFC systems are implemented, then drag reduction is achieved, but system complexity increases
Solution Approach 1:
The ALFC system components (suction ports, plenum chambers, ducting) are merged with the nacelle structure, eliminating separate housings and reducing the number of interfaces and connections. This integration maintains the drag reduction functionality while simplifying the overall system architecture and reducing complexity.
3Weight of moving object
If composite panel structures are used, then weight reduction is achieved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs composite panel structures for the nacelle construction, which provide high strength-to-weight ratio and design flexibility. The composite materials allow for integrated formation of suction ports and plenum chambers during molding, reducing post-manufacturing operations and maintaining precision requirements at acceptable levels while achieving significant weight reduction.
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 promotes laminar flow, reducing drag and weight while improving manufacturing feasibility, thereby enhancing aircraft propulsion efficiency and reducing commercial implementation challenges.
Implementation Method 1
The plenum duct is also fluidly coupled with a suction device, which draws air into the plenum duct through the perforations in the outer surface
Implementation Method 2
This modification generally removes low energy air from a boundary layer along an extent of the outer surface to prevent that boundary layer from thickening and eventually tripping into a turbulent flow
Data Source
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AI summary
An assembly (76) is provided for active laminar flow control. This assembly (76) includes a panel (94), which panel (94) includes an outer skin (68), an inner skin (96) and a plurality of plenums (80A, 80B) between the outer skin (68) and the inner skin (96). Each of the plurality of plenums (80A, 80B) is fluidly coupled with a respective array of perforations (78) through the outer skin (68). The panel (94) is constructed from fiber-reinforced composite material.