Experimental investigation of spray cooling on steel plates with periodic micropillar structures: Two-stage quenching phenomenon

Hiroyuki Fukuda; Yutaku Kita; Takaaki Ariyoshi; Yasuyuki Takata; Masamichi Kohno

doi:10.1016/j.applthermaleng.2025.126870

Experimental investigation of spray cooling on steel plates with periodic micropillar structures: Two-stage quenching phenomenon

Hiroyuki Fukuda, Yutaku Kita^*, Takaaki Ariyoshi, Yasuyuki Takata, Masamichi Kohno

^*Corresponding author for this work

Engineering

Research output: Contribution to journal › Article › peer-review

8 Downloads (Pure)

Abstract

In this study, water spray cooling tests were conducted on stainless steel samples with micropillars fabricated using a laser texturing method. The micropillars had a fixed pitch of 100 µm and varied in width (10–80 µm) and height (30–150 µm). The experiments revealed two distinct stages of quenching, observed as abrupt increases in the heat transfer rate during cooling from 700 °C to 100 °C on the micropillared samples. The first quench occurred at temperatures above 400 °C, as evaluated at the base of the pillars based on thermocouple readings, and was followed by a second quench at approximately 280 °C. The first quench was attributed to the onset of stable liquid–solid contact on the tops of the micropillars, enabled by significant temperature drops within the pillars. The wetting front subsequently advanced from the pillar tips to their bases, eventually covering the entire surface and resulting in the second quenching event. Taller micropillars were found to increase the “apparent” first quench temperature due to the longer heat conduction path through the pillars, which allowed stable wetting at the tips while maintaining higher temperatures at the bases. In contrast, shorter micropillars exhibited a gradual increase in cooling rate without a distinct first quench point. Increasing the micropillar width up to 30 µm (for a height of 50 µm) improved cooling performance due to the enhanced heat transfer area at the pillar tips. However, further increasing the width led to diminished performance, with heat transfer characteristics resembling those of a smooth sample. The second quench consistently occurred at approximately 280 °C, similar to the smooth sample, regardless of the pillar geometry.

Original language	English
Article number	126870
Journal	APPLIED THERMAL ENGINEERING
Volume	275
Early online date	21 May 2025
DOIs	https://doi.org/10.1016/j.applthermaleng.2025.126870
Publication status	E-pub ahead of print - 21 May 2025

Keywords

Micropillars
Quenching
Spray cooling
Surface roughness

Access to Document

10.1016/j.applthermaleng.2025.126870Licence: CC BY

Experimental investigation of spray_FUKUDA_Publishedonline21May2025_GOLD_VoR (CC BY)Final published version, 10.8 MBLicence: CC BY

Cite this

@article{8a83e54cdf884db4a97ff1803a6a0dd7,

title = "Experimental investigation of spray cooling on steel plates with periodic micropillar structures: Two-stage quenching phenomenon",

abstract = "In this study, water spray cooling tests were conducted on stainless steel samples with micropillars fabricated using a laser texturing method. The micropillars had a fixed pitch of 100 µm and varied in width (10–80 µm) and height (30–150 µm). The experiments revealed two distinct stages of quenching, observed as abrupt increases in the heat transfer rate during cooling from 700 °C to 100 °C on the micropillared samples. The first quench occurred at temperatures above 400 °C, as evaluated at the base of the pillars based on thermocouple readings, and was followed by a second quench at approximately 280 °C. The first quench was attributed to the onset of stable liquid–solid contact on the tops of the micropillars, enabled by significant temperature drops within the pillars. The wetting front subsequently advanced from the pillar tips to their bases, eventually covering the entire surface and resulting in the second quenching event. Taller micropillars were found to increase the “apparent” first quench temperature due to the longer heat conduction path through the pillars, which allowed stable wetting at the tips while maintaining higher temperatures at the bases. In contrast, shorter micropillars exhibited a gradual increase in cooling rate without a distinct first quench point. Increasing the micropillar width up to 30 µm (for a height of 50 µm) improved cooling performance due to the enhanced heat transfer area at the pillar tips. However, further increasing the width led to diminished performance, with heat transfer characteristics resembling those of a smooth sample. The second quench consistently occurred at approximately 280 °C, similar to the smooth sample, regardless of the pillar geometry.",

keywords = "Micropillars, Quenching, Spray cooling, Surface roughness",

author = "Hiroyuki Fukuda and Yutaku Kita and Takaaki Ariyoshi and Yasuyuki Takata and Masamichi Kohno",

note = "Publisher Copyright: {\textcopyright} 2025 The Author(s)",

year = "2025",

month = may,

day = "21",

doi = "10.1016/j.applthermaleng.2025.126870",

language = "English",

volume = "275",

journal = "APPLIED THERMAL ENGINEERING",

issn = "1359-4311",

publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Experimental investigation of spray cooling on steel plates with periodic micropillar structures

T2 - Two-stage quenching phenomenon

AU - Fukuda, Hiroyuki

AU - Kita, Yutaku

AU - Ariyoshi, Takaaki

AU - Takata, Yasuyuki

AU - Kohno, Masamichi

PY - 2025/5/21

Y1 - 2025/5/21

N2 - In this study, water spray cooling tests were conducted on stainless steel samples with micropillars fabricated using a laser texturing method. The micropillars had a fixed pitch of 100 µm and varied in width (10–80 µm) and height (30–150 µm). The experiments revealed two distinct stages of quenching, observed as abrupt increases in the heat transfer rate during cooling from 700 °C to 100 °C on the micropillared samples. The first quench occurred at temperatures above 400 °C, as evaluated at the base of the pillars based on thermocouple readings, and was followed by a second quench at approximately 280 °C. The first quench was attributed to the onset of stable liquid–solid contact on the tops of the micropillars, enabled by significant temperature drops within the pillars. The wetting front subsequently advanced from the pillar tips to their bases, eventually covering the entire surface and resulting in the second quenching event. Taller micropillars were found to increase the “apparent” first quench temperature due to the longer heat conduction path through the pillars, which allowed stable wetting at the tips while maintaining higher temperatures at the bases. In contrast, shorter micropillars exhibited a gradual increase in cooling rate without a distinct first quench point. Increasing the micropillar width up to 30 µm (for a height of 50 µm) improved cooling performance due to the enhanced heat transfer area at the pillar tips. However, further increasing the width led to diminished performance, with heat transfer characteristics resembling those of a smooth sample. The second quench consistently occurred at approximately 280 °C, similar to the smooth sample, regardless of the pillar geometry.

AB - In this study, water spray cooling tests were conducted on stainless steel samples with micropillars fabricated using a laser texturing method. The micropillars had a fixed pitch of 100 µm and varied in width (10–80 µm) and height (30–150 µm). The experiments revealed two distinct stages of quenching, observed as abrupt increases in the heat transfer rate during cooling from 700 °C to 100 °C on the micropillared samples. The first quench occurred at temperatures above 400 °C, as evaluated at the base of the pillars based on thermocouple readings, and was followed by a second quench at approximately 280 °C. The first quench was attributed to the onset of stable liquid–solid contact on the tops of the micropillars, enabled by significant temperature drops within the pillars. The wetting front subsequently advanced from the pillar tips to their bases, eventually covering the entire surface and resulting in the second quenching event. Taller micropillars were found to increase the “apparent” first quench temperature due to the longer heat conduction path through the pillars, which allowed stable wetting at the tips while maintaining higher temperatures at the bases. In contrast, shorter micropillars exhibited a gradual increase in cooling rate without a distinct first quench point. Increasing the micropillar width up to 30 µm (for a height of 50 µm) improved cooling performance due to the enhanced heat transfer area at the pillar tips. However, further increasing the width led to diminished performance, with heat transfer characteristics resembling those of a smooth sample. The second quench consistently occurred at approximately 280 °C, similar to the smooth sample, regardless of the pillar geometry.

KW - Micropillars

KW - Quenching

KW - Spray cooling

KW - Surface roughness

UR - http://www.scopus.com/inward/record.url?scp=105005486297&partnerID=8YFLogxK

U2 - 10.1016/j.applthermaleng.2025.126870

DO - 10.1016/j.applthermaleng.2025.126870

M3 - Article

AN - SCOPUS:105005486297

SN - 1359-4311

VL - 275

JO - APPLIED THERMAL ENGINEERING

JF - APPLIED THERMAL ENGINEERING

M1 - 126870

ER -

Experimental investigation of spray cooling on steel plates with periodic micropillar structures: Two-stage quenching phenomenon

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this