TY - JOUR
T1 - Natural convection in square enclosure induced by inner circular cylinder with time-periodic pulsating temperature
AU - Huang, Zhu
AU - Zhang, Wei
AU - Xi, Guang
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2015/3
Y1 - 2015/3
N2 - The periodic unsteady natural convection flow and heat transfer in a square enclosure containing a concentric circular cylinder is numerically studied. The temperature of the inner circular cylinder fluctuates periodically with time at higher averaged value while the temperature of the enclosure keeps lower constant, and the natural convection is driven by the temperature difference. The two-dimensional natural convection is simulated with high accuracy temporal spectral method and local radial basis functions method. The Rayleigh number is studied in the range 103 ≤ Ra ≤ 106, the temperature pulsating period ranges from 0.01 to 100 and the temperature pulsating amplitudes are a = 0.5, 1.0 and 1.5. Numerical results reveal that the fluid flow and heat transfer is strongly dependent on the pulsating temperature of inner cylinder. Comparing with the steady state natural convection, the heat transfer is enhanced generally for the time-periodic unsteady natural convection, and the local maximum heat transfer rate is observed for Ra = 105 and 106. Moreover, the phenomenon of backward heat transfer is discussed quantitatively. Also, the influence of pulsating temperature on the unsteady fluid flow and heat transfer are discussed and analyzed.
AB - The periodic unsteady natural convection flow and heat transfer in a square enclosure containing a concentric circular cylinder is numerically studied. The temperature of the inner circular cylinder fluctuates periodically with time at higher averaged value while the temperature of the enclosure keeps lower constant, and the natural convection is driven by the temperature difference. The two-dimensional natural convection is simulated with high accuracy temporal spectral method and local radial basis functions method. The Rayleigh number is studied in the range 103 ≤ Ra ≤ 106, the temperature pulsating period ranges from 0.01 to 100 and the temperature pulsating amplitudes are a = 0.5, 1.0 and 1.5. Numerical results reveal that the fluid flow and heat transfer is strongly dependent on the pulsating temperature of inner cylinder. Comparing with the steady state natural convection, the heat transfer is enhanced generally for the time-periodic unsteady natural convection, and the local maximum heat transfer rate is observed for Ra = 105 and 106. Moreover, the phenomenon of backward heat transfer is discussed quantitatively. Also, the influence of pulsating temperature on the unsteady fluid flow and heat transfer are discussed and analyzed.
UR - http://hdl.handle.net/10754/566139
UR - https://linkinghub.elsevier.com/retrieve/pii/S0017931014010163
UR - http://www.scopus.com/inward/record.url?scp=84913546229&partnerID=8YFLogxK
U2 - 10.1016/j.ijheatmasstransfer.2014.11.044
DO - 10.1016/j.ijheatmasstransfer.2014.11.044
M3 - Article
SN - 0017-9310
VL - 82
SP - 16
EP - 25
JO - International Journal of Heat and Mass Transfer
JF - International Journal of Heat and Mass Transfer
ER -