NATURAL CONVECTION OF WATER NEAR 4 degrees C INSIDE PARTIALLY HEATED AND COOLED VERTICAL WALLS

EZAN M. A., Kalfa M.

ISI BILIMI VE TEKNIGI DERGISI-JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY, cilt.37, sa.1, ss.1-12, 2017 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 37 Sayı: 1
  • Basım Tarihi: 2017
  • Dergi Adı: ISI BILIMI VE TEKNIGI DERGISI-JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Sayfa Sayıları: ss.1-12
  • Anahtar Kelimeler: Transient natural convection, Density inversion, Partial heating/cooling, Aspect ratio, BUOYANCY-DRIVEN CONVECTION, DENSITY MAXIMUM, RECTANGULAR ENCLOSURE, SQUARE ENCLOSURE, SIDE WALLS, CAVITY, NANOFLUIDS, INVERSION, STORAGE, FLOW
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

In this study, transient heat transfer process inside a two-dimensional cavity has been numerically investigated. The numerical model has been created with control volume approach by using C++ programming language. In order to determine the accuracy of the numerical code, comparisons are made with the results of the numerical analysis and experimental velocity measurements from the literature. After that, the time-dependent variations of local and average Nusselt numbers have been revealed for various aspect ratios and different thermal boundary conditions of the cavity. The interaction of temperature and velocity distributions by different boundary conditions has been examined. In cold storage applications, water temperature decreases below the density inversion temperature and the natural convection of water becomes more complicated. Nevertheless, the majority of the models that are developed to simulate the cold storage units in the literature reduce the heat transfer mechanism into conduction mode to simplify the complexity of the coupled governing equations, so that take advantage of decreasing the computational time. Neglecting the complex convection currents may lead erroneous predictions. In this regard, the results of the current work will guide the researchers and the design engineers working on the cold storage applications with water as a storage medium.