Publication Date:
2019
Description:
〈p〉Publication date: September 2019〈/p〉
〈p〉〈b〉Source:〈/b〉 Applied Thermal Engineering, Volume 160〈/p〉
〈p〉Author(s): Wenwu Zhou, Lin Yuan, Xin Wen, Yingzheng Liu, Di Peng〈/p〉
〈div xml:lang="en"〉
〈h5〉Abstract〈/h5〉
〈div〉〈p〉The present study explored and examined the piezoelectric (PE) jet: an active cooling concept that can be actuated in demand, which had an oscillating flow and extremely low power consumption. The heat transfer and flow characteristics of the PE jet were quantified at various Reynolds numbers (〈em〉Re〈/em〉 = 5000, 10,000, 18,000) and spacings (〈em〉H〈/em〉/〈em〉D〈/em〉 = 4.5, 5.5, 6.5; corresponding gap 〈em〉G〈/em〉/〈em〉D〈/em〉 = 0.1, 1.1, 2.1). The temperature sensitive paint technique was used to study the heat transfer, and the particle image velocimetry technique was applied to resolve the flow characteristics and to further correlate the heat transfer results. Measured results show that the impingement cooling of the PE jet increased as the 〈em〉Re〈/em〉 increased and as the 〈em〉H〈/em〉/〈em〉D〈/em〉 decreased. Compared with a circular jet, the PE jet exhibited a greatly improved heat transfer at 〈em〉H〈/em〉/〈em〉D〈/em〉 = 4.5 (i.e., 〈em〉G〈/em〉 = 0.1〈em〉D〈/em〉), with a maximum of 20% enhancement in area-averaged 〈em〉Nu〈/em〉. Due to the fan oscillation, the turbulent kinetic energy level in the PE jet was significantly higher than in the circular jet, which greatly promoted the heat transfer at a narrow gap. In general, the new PE jet can provide superior heat transfer performance at a small gap and a high Reynolds number.〈/p〉〈/div〉
〈/div〉
Print ISSN:
1359-4311
Electronic ISSN:
1873-5606
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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