Convective Heat Transfer Enhancement through Laser-Etched Heat Sinks: Elliptic Scale-Roughened and Cones Patterns

Abstract

The efficient dissipation of localized heat flux by convection is a key request in several engineering applications, especially electronic ones. The recent advancements in manufacturing processes are unlocking the design and industrialization of heat exchangers with unprecedented geometric characteristics and, thus, performance. In this work, laser etching manufacturing technique is employed to develop metal surfaces with designed microstructured surface patterns. Such precise control of the solid-air interface (artificial roughness) allows to manufacture metal heat sinks with enhanced thermal transmittance with respect to traditional flat surfaces. Here, the thermal performance of these laser-etched devices is experimentally assessed by means of a wind tunnel in a fully turbulent regime. At the highest Reynolds number tested in the experiments ( R e L ≈ 16 , 500 ), elliptic scale-roughened surfaces show thermal transmittances improved by up to 81% with respect to heat sinks with flat surface. At similar testing conditions, cones patterns provide an enhancement in Nusselt number and thermal transmittance of up to 102% and 357%, respectively. The latter results are correlated with the main geometric and thermal fluid dynamics descriptors of the convective heat transfer process in order to achieve a predictive model of their performance. The experimental evidence shown in this work may encourage and guide a broader use of micro-patterned surfaces for enhancing convective heat transfer in heat exchangers.

A Perspective on the Molecular Modeling of Electrolyte Decomposition Reactions for Solid Electrolyte Interphase Growth in Lithium‐Ion Batteries

“…The SEI growth is believed to be diffusion‐controlled, either through electrolyte diffusion from the bulk to the SEI [ 13–17 ] or through the diffusion of electrons from the anode to the SEI. Three main electron transport mechanisms from the anode to the electrolyte can be distinguished.…”

Bibliographic Review: The Influence of Obstacles Inside the Ducts on the Flow Proprieties

“…Obstacles are employed in a wide variety of heat exchange applications, such as heat exchangers [13], gas turbine blade cooling devices, solar air heaters [14], and cooling devices for electronic components [15]. Thus, many studies have been conducted to examine the effects of obstacles on increased heat transfer.…”

Textured and Rigid Capillary Materials for Passive Energy‐Conversion Devices

“…[2] Engineering the capillary properties of porous materials has been pursued to achieve improved thermal, [3] mechanical, [4] electrical, [5] optical, [6] and biomedical [7] performance. In addition to intrinsically porous materials (e.g., metal organic frameworks [8] ), the recent research has focused on manufacturing processes that can control finely either material addition (e.g., 3D printing [1,9] ) or removal (e.g., laser etching [6,10] ) from bulk materials to design a precise pores architecture.Porous materials with engineered multi-functionalities are particularly desirable for passive energy-conversion devices. These devices typically do not require high quality energy inputs and, due to the absence of moving mechanical parts, require low maintenance, and are cost-effective.…”

“…[2] Engineering the capillary properties of porous materials has been pursued to achieve improved thermal, [3] mechanical, [4] electrical, [5] optical, [6] and biomedical [7] performance. In addition to intrinsically porous materials (e.g., metal organic frameworks [8] ), the recent research has focused on manufacturing processes that can control finely either material addition (e.g., 3D printing [1,9] ) or removal (e.g., laser etching [6,10] ) from bulk materials to design a precise pores architecture.…”