Viscoelastic Fluid Cooling with Obstruction-Induced Instabilities

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current thermal solutions for data processing and wireless communication devices face challenges in scaling to meet increasing heat demands without requiring unduly high pumping pressures, as they often rely on microchannel cooling technologies that increase heat transfer but also increase fluid resistance.

Innovation Solution

The use of viscoelastic fluids in conduits with strategically placed obstructions generates local instabilities in fluid flow, enhancing heat transfer at specific locations while maintaining laminar flow elsewhere, thus reducing pumping requirements and allowing for efficient cooling without significantly increasing device size or pressure drop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If microchannel cooling technologies are used to increase heat transfer surface area, then heat transfer capability is improved, but fluid resistance and pumping pressure requirements increase

Engineering Contradiction:
Improveheat transfer capabilityVSAvoidpumping pressure
Core Design Contradiction:
TemperatureVSStress or pressure

Solution Approach 1:

The patent applies local quality by placing obstructions only at specific locations within the conduit where hot spots are predicted to occur, rather than throughout the entire conduit. This creates localized instabilities and enhanced heat transfer only where needed, while maintaining laminar flow and low resistance in other regions. The obstruction locations are determined by predicting hot spot locations based on heat source characteristics.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by implementing obstructions that only partially block the fluid flow path rather than completely obstructing it. The obstructions are designed to extend only partway across the conduit dimension, creating sufficient flow disturbance to generate instabilities and enhance heat transfer while allowing enough flow through to avoid excessive pressure drop. This partial blocking approach balances heat transfer enhancement with acceptable pumping requirements.

Inventive Principle:
Principle #16Partial or excessive action

2Temperature

If obstructions are added to generate turbulence and increase heat transfer, then heat transfer is improved, but device complexity increases

Engineering Contradiction:
Improveheat transferVSAvoidconduit structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the conduit into multiple sections, with obstructions placed only in specific segments where hot spots are predicted to occur. Rather than placing obstructions throughout the entire conduit length, the system segments the cooling function into targeted zones, reducing overall device complexity while maintaining effective heat transfer where needed. The segmented approach allows simpler conduit design in regions without obstructions.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If thermally reactive obstructions are used to accommodate transient hot spots, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improveresponse to transient hot spotsVSAvoidobstruction mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by using thermally reactive obstruction material whose physical properties (such as shape, volume, or position) change in response to temperature variations. The obstruction material expands, contracts, or deforms based on local temperature conditions, automatically adjusting the degree of flow blockage and instability generation to match transient heat load conditions. This passive thermal response provides adaptability without complex active control mechanisms.

Inventive Principle:
Principle #35Parameter changes

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

This approach enables efficient local cooling of heat sources with high heat fluxes, reducing the need for high pumping powers and maintaining a low profile, making it suitable for compact devices like processors and laser devices, while also accommodating transient hot spots through thermally reactive obstructions.

Implementation Method 1

a viscoelastic fluid operable to flow through said conduit and to transfer heat from a heat source in thermal contact with said conduit

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

transfer heat from a heat source in thermal contact with said conduit

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

said obstruction being configured to partially block fluid flow and generate local instabilities in said fluid flow upstream of said obstruction thereby increasing heat transfer

Methodology Applied
Scientific EffectFlow instability: Turbulence

Implementation Method 4

Viscoelastic fluids generally have a higher viscosity than many Newtonian fluids such as water and may also be less predictable in their properties and behaviour

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 5

owing to the way their viscosity changes with shear, obstructions in a conduit can be used to cause instabilities in the flow path upstream of the obstacle

Methodology Applied
Scientific EffectShear thinning: Shear Thinning

Implementation Method 6

The viscosity of the fluid will act to dampen these instabilities and thus, laminar flow will be attained again downstream

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP3096352B1A heat transfer method and device
Publication Date: 2018.02.21 ALCATEL LUCENT SA
  • EP3096352B1 patent drawingFigure 1~2
  • EP3096352B1 patent drawingFigure 3
  • EP3096352B1 patent drawingFigure 4

AI summary

A heat transfer device and method is disclosed. The heat transfer device comprises: a conduit having at least one mini dimension of less than 1 cm; and a viscoelastic fluid operable to flow through the conduit and to transfer heat from a heat source in thermal contact with the conduit. The conduit comprises one or more obstructions arranged at locations in the conduit, the obstructions are configured to partially block fluid flow and generate local instabilities in the fluid flow upstream of the obstruction thereby increasing heat transfer from the heat source at a location upstream of the predetermined location.