Pulsating hybrid nanofluids double slot jets impingement onto an isothermal wall


SELİMEFENDİGİL F.

Heat Transfer Research, vol.49, no.2, pp.173-188, 2018 (SCI-Expanded, Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 2
  • Publication Date: 2018
  • Doi Number: 10.1615/heattransres.2017015650
  • Journal Name: Heat Transfer Research
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.173-188
  • Keywords: Heat transfer enhancement, Hybrid nanofluids, Pulsating impinging jet
  • Manisa Celal Bayar University Affiliated: Yes

Abstract

In the present work, a numerical study of oscillating rectangular double slot jets subjected to Al2O3–Cu–water hybrid nanofluid is conducted. The unsteady governing equations are solved by a finite volume based commercial solver. The effects of pulsating frequency, Reynolds number in the laminar flow regime on the heat transfer characteristics are numerically investigated. It is observed that both in the steady flow and pulsating flow case, the stagnation point Nusselt number increases with the Reynolds number. More recirculation bubbles are formed on the bottom wall and on the top wall, and their complicated interactions cause the fluctuation of the local peak in the Nusselt number for the lowest frequency in the pulsating flow case. At f = 0.5 Hz, heat transfer enhancements of 7.76%, 5.75%, and 6.52% are obtained in pulsating flow compared to the steady flow case for a Reynolds number of 250, 500, and 750, respectively.