Additive Heat Exchanger Tubes With Selective Surface Roughness
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Solution Overview
Problem
Aviation heat exchanger designs face challenges in balancing weight, size, and performance requirements, with existing technologies struggling to optimize geometry for efficient fluid flow, heat transfer, and pressure drop.
Innovation Solution
The use of additive manufacturing to create heat exchanger cores with selectively roughened inner and outer surfaces, featuring airfoil-shaped tubes with strategically placed roughened regions on the outer and inner surfaces to induce turbulence and varied cross-sectional areas to enhance heat transfer and manage pressure drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If additive manufacturing is used to create heat exchanger cores with selective surface roughness, then heat transfer efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies selective surface roughness to specific regions of the heat exchanger tubes rather than uniform roughness across the entire surface. The roughened regions are strategically positioned at leading edges and in high-heat-transfer zones, while trailing edges and low-heat-transfer zones maintain smooth surfaces. This local differentiation optimizes heat transfer efficiency where needed while minimizing the overall manufacturing complexity and material usage.
2Loss of energy
If tube geometry is optimized for efficient fluid flow, then pressure drop is reduced, but heat transfer surface area is compromised
Solution Approach 1:
The patent implements different surface characteristics at different locations along the tube length. Leading edges feature roughened surfaces to promote turbulence and enhance heat transfer, while trailing edges maintain smooth surfaces to minimize pressure drop. This spatial differentiation allows the heat exchanger to achieve both efficient heat transfer and low pressure loss simultaneously.
Solution Approach 2:
The patent employs airfoil-shaped tube cross-sections with curved surfaces that are optimized for fluid flow. The airfoil geometry reduces flow separation and turbulence-induced pressure losses while maintaining effective heat transfer surfaces. The curved leading edges and tapered trailing edges create favorable flow patterns that balance heat transfer efficiency with pressure drop minimization.
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 optimizes heat exchanger efficiency by improving fluid flow, reducing flow resistance, and enhancing heat transfer while managing pressure drops, thereby limiting metal temperatures within design constraints.
Implementation Method 1
strategically placed roughened regions to induce turbulence and varied cross-sectional areas, optimizing fluid flow, pressure drop, and heat transfer
Implementation Method 2
a heat exchanger core comprises a first fluid inlet side and a second fluid outlet side along which a first fluid F1 is received
Data Source
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AI summary
A heat exchanger core comprises a plurality of tubes (20) extending along a first fluid axis, each of the plurality of tubes comprising a leading edge (24), a trailing edge (26) opposite the leading edge, and a pair of oppositely disposed sidewalls (28) extending from the leading edge to the trailing edge. The leading edge, trailing edge, and the pair of sidewalls define an inner surface (30) and an outer surface (32) of each of the plurality of tubes. Each of a first subset of the plurality of tubes further comprises a roughened region (34, 36) on the outer surface of one of the pair of sidewalls.