Osman TURAN
(Bursa Teknik Üniversitesi, Makine Mühendisliği Bölümü, Bursa, Türkiye)
Yıl: 2020Cilt: 6Sayı: 1ISSN: 2148-7847Sayfa Aralığı: 1 - 15İngilizce

61 0
NUMERICAL INVESTIGATION OF LAMINAR MIXED CONVECTION IN A SQUARE CROSS-SECTIONED CYLINDRICAL ANNULAR ENCLOSURE
Steady-state laminar mixed convection of Newtonian fluids in a square cross-sectioned cylindrical annular enclosure with rotating inner wall and heated top cover has been numerically analysed based on axisymmetric incompressible flow simulations. Richardson number, Reynolds number and 𝑟𝑖/𝑅 effects on heat and momentum transport have been investigated for the range of Richardson number 0 ≤ 𝑅𝑖 ≤ 1, Reynolds number 500 ≤ 𝑅𝑒 ≤ 2000 and 0.25 ≤ 𝑟𝑖/𝑅 ≤ 8 at a representative value of Prandtl number (i.e. 𝑃𝑟 = 1.0). A scaling analysis has been also carried out in order to elucidate the possible influences of Reynolds, Richardson and Prandtl numbers and 𝑟𝑖/𝑅 on the mean Nusselt number. It has been found that the mean Nusselt number 𝑁𝑢 ̅̅̅̅ demonstrates a monotonically decreasing trend with increasing 𝑅𝑖 whereas 𝑁𝑢 ̅̅̅̅ increases with increasing 𝑟𝑖/𝑅 and 𝑅𝑒 which is consistent with scaling estimation. It is also observed that the flow pattern in the case of purely forced convection (i.e. 𝑅𝑖 = 0) is significantly different from those in mixed convection (i.e. 𝑅𝑖 > 0). In the case of 𝑅𝑖 = 0 (i.e. purely forced convection), a one-cell flow structure with two small vortexes on the top corners is observed for 𝑟𝑖/𝑅 ≤ 1, whereas a second cell appears in the flow field for 𝑟𝑖/𝑅 > 1 at 𝑅𝑒 = 1000. On the other hand, in the case of mixed convection (i.e. 𝑅𝑖 > 0), two-cell and four-cell flow structures occur in the flow field depending on 𝑅𝑖 and 𝑟𝑖/𝑅 for the range of 𝑅𝑖, Re and 𝑟𝑖/𝑅 considered here at 𝑃𝑟 = 1.0. Based these observations, a flow regime diagram has been proposed here for mixed convection (i.e. 𝑅𝑖 > 0) for the range of 𝑅𝑖, 𝑅𝑒 and 𝑟𝑖/𝑅 analysed in this study
DergiAraştırma MakalesiErişime Açık
  • [1] Zandbergen PJ, Dikstra D. Von Karman swirling flows. Annual Reviews Fluid Mechanics 1987;19:465-491. https://doi.org/10.1146/annurev.fl.19.010187.002341
  • [2] Vogel HU, Experimentelle Ergebnisse über die laminare Strömung in einem zylindrischen Gahause mit darin rotieren-der Scheibe. MPI Bericht 6; 1968.
  • [3] Vogel HU, Rückströmungsblasen in Drallsströmungen. Festschrift 50 Jahre Max-Planck-Institut für Strömungsforschung 1925-1975, 1975.
  • [4] Ronnenberg B. Ein selbstjustierendes 3-Komponenten-Laserdoppleranemometer nach dem Vergleichsstrahlverfahren, angewandt für Untersuchungen in einer stationaren sylinder-symmetrischen Drehströmung mit einem Rückstromgebiet. MPI Bericht 20, 1977.
  • [5] Bertela M, Gori F. Laminer flow in a cylindrical container with a rotating cover. Journal of Fluids Engineering 1982;104:31-39. https://doi.org/10.1115/1.3240849.
  • [6] Escudier MP. Observations of the flow produced in a cylindrical container by rotating endwall. Experiments in Fluids 1984;2:189-196. https://doi.org/10.1007/BF00571864.
  • [7] Lugt HJ, Haussling HJ. Axisymmetric vortex breakdown in rotating fluid within a container. Journal of Applied Mechanics 1982;49:921-923. https://doi.org/10.1115/1.3162645.
  • [8] Lopez JM. Axisymmetric vortex breakdown: Part1. Confined swirling flow. Journal Fluid Mechanics 1990;221: 533-552. https://doi.org/10.1017/S0022112090003664.
  • [9] Kim WN, Hyun JM. Convective heat transfer in a cylinder with a rotating lid under stable stratification. Int J of Heat and Fluid Flow 1997;18:384-388. https://doi.org/10.1016/S0142-727X(97)00012-X.
  • [10] Lee CH, Hyun JM. Flow of a stratified fluid in a cylinder with a rotating lid. Int J of Heat and Fluid Flow 1999;20: 26-33. https://doi.org/10.1016/S0142-727X(98)10041-3.
  • [11] Iwatsu R. Flow pattern and heat transfer of swirling flows in cylindrical container with rotating top and stable temperature gradient. International Journal of Heat and Mass Transfer 2004; 47: 2755-2767. https://doi.org/10.1016/j.ijheatmasstransfer.2003.11.032.
  • [12] Escuider MP, O’Leary J, Poole RJ. Flow produced in a conical container by a rotating end wall. Int J of Heat and Fluid Flow 2007;28:1418-1428. https://doi.org/10.1016/j.ijheatfluidflow.2007.04.018
  • [13] Turan O, Yigit S, Chakraborty N. Effects of wall heating on laminar mixed convection in a cylindrical enclosure with a rotating end wall. Journal of Thermal Science 2018;131:80-93. https://doi.org/10.1016/j.ijthermalsci.2018.05.005
  • [14] Patankar SV. Numerical Heat Transfer and Fluid Flow. Hemisphere, Washington, D.C; 1980.

TÜBİTAK ULAKBİM Ulusal Akademik Ağ ve Bilgi Merkezi Cahit Arf Bilgi Merkezi © 2019 Tüm Hakları Saklıdır.