Substrate Cooling Recesses for Vortex Heat Transfer With Low Pressure Loss

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Solution Overview

Problem

Conventional cooling apparatuses for electronic components face challenges in reducing size and minimizing pressure loss while maintaining efficient heat radiation due to the extended length of heat-radiating members and limited contact area with the cooling fluid.

Innovation Solution

A heat-radiating system incorporating a vortex flow generating portion with recesses on the substrate surface, where the recess depth and laminar sub-layer thickness satisfy specific relations, promoting vortex flow and efficient heat transfer under controlled fluid flow conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If heat-radiating members are extended in length to increase contact area with cooling fluid, then heat radiation efficiency is improved, but apparatus size increases

Engineering Contradiction:
Improveheat radiation efficiencyVSAvoidapparatus size
Core Design Contradiction:
ProductivityVSLength of stationary object

Solution Approach 1:

The invention transitions from extending heat-radiating members in one dimension (length) to creating vortex flow structures on the substrate surface. By forming recesses that generate rotational flow patterns, the cooling effectiveness is enhanced through a different dimensional approach - utilizing surface topology and fluid dynamics rather than simply increasing contact area through extension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The invention changes the flow regime parameter from laminar to vortex flow by introducing recesses with specific depth-to-width ratios. This parameter change in flow characteristics enhances heat transfer coefficient without requiring increased apparatus size, as the vortex motion intensifies fluid mixing and heat exchange at the existing contact area.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If heat-radiating members are extended to increase cooling effectiveness, then heat transfer is improved, but pressure loss of cooling fluid increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidpressure loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The recesses generate vortex flow that creates rotational motion and turbulence in the cooling fluid. This mechanical motion enhances heat transfer by disrupting thermal boundary layers and increasing fluid mixing, achieving improved heat transfer efficiency without the excessive pressure losses associated with simply extending heat-radiating members.

Inventive Principle:
Principle #18Mechanical vibration

3Productivity

If vortex flow is generated using recesses, then heat transfer is promoted, but manufacturing complexity increases

Engineering Contradiction:
Improveheat transfer coefficientVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Instead of making the entire heat-radiating structure complex, the invention applies vortex-generating recesses only at specific locations on the substrate surface. This localized approach promotes heat transfer where most needed while keeping the overall structure simple and maintaining ease of manufacture for the bulk of the component.

Inventive Principle:
Principle #3Local quality

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 system achieves reduced apparatus size, lower pressure loss, and enhanced heat radiation efficiency through promoted heat transfer, with the vortex flow structure effectively agitating the cooling fluid and increasing the heat transfer coefficient.

Implementation Method 1

a vortex flow generating portion on a surface of the substrate that is in contact with the cooling fluid, the vortex flow generating portion comprising a plurality of recesses that extend in a direction intersecting the flow direction of the cooling fluid and cause a vortex flow depending on a flow condition of the cooling fluid

Methodology Applied
Scientific EffectVortex flow: Vortex Ring

Implementation Method 2

heat exchange between a substrate and cooling fluid

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3054479B1Heat-radiating system
Publication Date: 2023.12.27 NISSAN MOTOR CO LTD
  • EP3054479B1 patent drawingFigure 1
  • EP3054479B1 patent drawingFigure 2(A)~2(B)
  • EP3054479B1 patent drawingFigure 3

AI summary

The heat-radiating system which radiates heat by heat exchange between a substrate 22 and cooling fluid. The heat-radiating system has a cooling structure that includes a vortex flow generating portion C1 on the surface of the substrate 22 in contact with the cooling fluid. The vortex flow generating portion C1 is composed of a plurality of recesses 22b that extend in the direction β intersecting the flow direction of the cooling fluid and causes a vortex flow depending on the flow condition of the cooling fluid. The recess depth H of the vortex flow generating portion and the laminar sub-layer thickness δb near the wall surface satisfy the relation of H > δb = 63.5/(Re7/8)×d (where Re is the Reynolds number, d is the characteristic length, and the Reynolds number is Re = ud/v where v is the kinematic viscosity of the cooling fluid, u is the flow velocity of the cooling fluid and d is the characteristic length), and operation of the heat radiating system is controlled such that the flow conditions of the cooling fluid fall within the range in which the relation of u/v ≤ 206×d1/7 (where u, v and d are as defined above) is satisfied.