Case studies on local mixed convection heat transfer coefficients along a radiant heated wall subjected to displacement ventilation


Camci M., Karakoyun Y., Açıkgöz Ö., Dalkılıç A. S.

Journal of Thermal Analysis and Calorimetry, vol.148, no.15, pp.7845-7854, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 148 Issue: 15
  • Publication Date: 2023
  • Doi Number: 10.1007/s10973-023-12262-6
  • Journal Name: Journal of Thermal Analysis and Calorimetry
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Index Islamicus, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.7845-7854
  • Keywords: Displacement ventilation, Local convective heat transfer coefficient, Mixed convection, Radiant heated wall, Temperature gradient
  • Yıldız Technical University Affiliated: Yes

Abstract

As the demand for energy-efficient air conditioning systems enabling thermal comfort criteria increases, the research into innovative systems that combine displacement ventilation and radiant heating is being more up-to-date. This work discusses local mixed convection heat transfer coefficients over a radiant heated wall in an experimental room coupled with displacement ventilation provided by a floor level nozzle. In the experimental chamber, the air enters the room either from the floor level of the analyzed heated wall as in scenario 1 or the opposite wall in scenario 2 in the upward direction. The intervals of air inlet temperature and velocity are set between 13–27 °C and 0–2.5 ms−1, respectively. The obtained data have been analyzed from a physical point of view, and four correlations having R-sq. numbers of 0.93, 0.94, 0.94, and 0.98 have been developed for the local mixed convective heat transfer coefficients along a heated wall. The alterations of local convection heat transfer coefficients along an examined radiant heated wall affected by a slot diffuser delivering a lowest air inlet velocity of 0.5 ms−1 and highest air inlet velocity of 2.5 ms−1 are gained in the intervals of 2–5.8 Wm−2 K−1 and 2.5–10 W m−2 K−1, in turn.