Additive Manufactured Heat Exchanger Core with Curved Unit Cells

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing heat transfer coolers, such as EGR coolers, face challenges in manufacturing complex core geometries without forming support structures, which leads to increased flow resistance, pressure drop, and manufacturing costs due to limitations in additive manufacturing technology.

Innovation Solution

A core body with interconnected unit cells featuring curved sidewalls and orifices, allowing for thermal energy transfer between fluids without mixing, and utilizing a flexible diaphragm for thermal expansion accommodation, enabling additive manufacturing without support structures and reducing flow resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If additive manufacturing is used to print complex repeating geometries with support structures, then structural integrity is maintained, but flow channels are clogged and manufacturing speed decreases

Engineering Contradiction:
Improvestructural integrityVSAvoidmanufacturing speed
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent extracts and eliminates the support structures from the additive manufacturing process by designing unit cells with overhanging surfaces that do not require support. The unit cell geometry is specifically configured so that all surfaces are either horizontal or slope upward from the build plate, allowing the core body to be printed without support structures that would otherwise clog flow channels and slow manufacturing.

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If unit cell size is reduced to avoid support structures, then design integrity is maintained, but flow resistance increases and manufacturing cost increases

Engineering Contradiction:
Improvedesign integrityVSAvoidflow resistance
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The patent applies local quality by configuring specific surfaces of the unit cells to have particular orientations relative to the build plate. The overhanging surfaces are designed to slope upward from the build plate, creating localized geometric properties that enable support-free manufacturing while maintaining large unit cell sizes for low flow resistance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The unit cells incorporate curved surfaces and rounded features that allow smooth material deposition during additive manufacturing without requiring support structures. The curved geometries maintain structural integrity while enabling larger cell sizes that reduce flow resistance through the core body.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Shape

If complex core geometries are manufactured using conventional casting, then tortuous flow channels are achieved, but manufacturing and assembly complexity increases

Engineering Contradiction:
Improvetortuous flow channelsVSAvoidmanufacturing and assembly
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent segments the core body into multiple unit cells arranged in a repeating pattern, where each unit cell is defined by four sidewalls meeting at edges. This segmentation allows the complex tortuous flow channel geometry to be achieved through simple, repeatable unit cell structures that are easier to manufacture using additive manufacturing compared to conventional casting of complex geometries.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges multiple unit cells together to form the complete core body, with edges of adjacent unit cells connecting to define continuous outer passageways. This merging approach creates complex tortuous flow channels through the combination of simple unit cell geometries, simplifying the manufacturing process compared to casting the entire complex geometry as a single piece.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances fluid throughput, reduces manufacturing costs, and increases the useful life of heat transfer apparatuses by accommodating thermal cycling and extreme temperatures, while eliminating the need for sliding interfaces and potential leak paths.

Implementation Method 1

The one or more sidewalls of the unit cells are configured to transport one or more of thermal energy from the first fluid or a component of the first fluid flowing in the inner passageways to the second fluid flowing in the outer passageways

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

utilizing a flexible diaphragm for thermal expansion accommodation, enabling additive manufacturing without support structures and reducing flow resistance

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4080037B1Core body for transfer apparatus and manufacturing the same
Publication Date: 2025.03.26 TRANSPORTATION IP HOLDINGS LLC
  • EP4080037B1 patent drawingFigure 1
  • EP4080037B1 patent drawingFigure 2
  • EP4080037B1 patent drawingFigure 3

AI summary

A core body includes a structure having a plurality of connected unit cells. At least one unit cell has one or more sidewalls that are curved and define a portion of an inner passageway within and through the unit cell. The one or more sidewalls define multiple orifices and include a cone disposed between at least some of the orifices. A dimple is defined along an outer surface of the unit cell at the cone. The outer surface at least partially defines an outer passageway that is sealed from the inner passageway by the one or more sidewalls. The one or more sidewalls are configured to transport one or more of thermal energy from a first fluid or a component of the first fluid flowing in the inner passageway to a second fluid flowing in the outer passageway without the first fluid mixing with the second fluid.