Water spray heat transfer through a piezoelectric atomizer with a single-hole micronozzle
- PDF / 2,787,673 Bytes
- 10 Pages / 595.22 x 842 pts (A4) Page_size
- 38 Downloads / 179 Views
DOI 10.1007/s12206-020-0735-x
Journal of Mechanical Science and Technology 34 (8) 2020 Original Article DOI 10.1007/s12206-020-0735-x Keywords: · Microspray cooling · Flow and thermal characteristics · Piezoelectric atomizer · Spray height · Surface initial temperature
Correspondence to: Shou-Shing Hsieh [email protected]
Citation: Hsieh, S.-S., Huang, C.-F., Lu, Y.-M. (2020). Water spray heat transfer through a piezoelectric atomizer with a single-hole micronozzle. Journal of Mechanical Science and Technology 34 (8) (2020) 3427~3436. http://doi.org/10.1007/s12206-020-0735-x
Received December 25th, 2019 Revised
April 20th, 2020
Accepted May 26th, 2020 † Recommended by Editor Yong Tae Kang
Water spray heat transfer through a piezoelectric atomizer with a single-hole micronozzle Shou-Shing Hsieh, Ching-Feng Huang and Yung-Ming Lu Department of Mechanical and Electromechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan 80424, ROC
Abstract
We report an experimental study on the flow and heat transfer for a single microhole of water spray impingement on an indium tin oxide (ITO) heating plate using a piezoelectric atomizer. A microhole of dj = 35 µm was used and tested with a volumetric flow rate of 0.22 cm3/min for three different spray heights of 10, 20 and 30 mm and five heater initial temperatures of 25 oC, 50 oC, 100 oC, 150 oC, and 200 oC. Through the optical measuring techniques of the microparticle image velocimetry (µPIV) as well as interferometric particle imaging (IPI) and micro laser-induced fluorescence (µLIF), the velocity field, such as spray centerline velocity, droplet impact velocity and impact crater diameter, including impinged liquid film thickness and heat transfer performance (CHF) can be measured and calculated. The effects of the spray height and initial heater temperature on the flow and thermal characteristics are presented and discussed herein. The experimental results show that both the spray centerline velocity and spray droplet impact velocity were significantly influenced by the initial surface temperature as well as by the spray height. As a result, the cooling performance would be, in turn, affected by the aforesaid two parameters.
1. Introduction
© The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany, part of Springer Nature 2020
Spray cooling is a very powerful thermal control tool which is frequently applied in power electronics, steelmaking, cryogenic dermatological cooling and emergency cooling systems applicable in power plants. Its heat removal capability has been proved to be as high as 1 kW/cm2 [1-3]. Many studies have examined spray cooling under different conditions [4-7]. However, a review of the literature reveals that very limited data are available for the impingement dynamics and associated heat transfer [8, 9], even though several papers have been published recently in this regard [10-13]. The complexities involved with the spray impacting including droplet dynamics, impingement liquid film thickness and
Data Loading...
