RT Journal Article
ID 10626ea948fd8865
A1 Wang, Xiaofeng
A1 Wang, Juntao
A1 Dai, Weizhong
T1 EFFECTS OF HEAT FLUX ON NATURAL CONVECTION OF WATER-BASED NANOFLUIDS IN A TRAPEZOIDAL ENCLOSURE
JF Heat Transfer Research
JO HTR
YR 2018
FD 2018-07-10
VO 49
IS 13
SP 1299
OP 1321
K1 heat transfer
K1 heat flux
K1 nanofluids
K1 natural convection
K1 trapezoidal enclosure
AB This study investigates natural convection heat transfer of water-based nanofluids in a trapezoidal enclosure where the
left vertical side is heated with constant heat flux both partially and throughout the entire wall, the inclined wall is
cooled, and the rest walls are kept adiabatic. The dimensionless governing equations were solved using a higher-order compact finite difference method, and solutions for algebraic equations were obtained through pesudo-time algorithms. Investigations of four types of nanofluids were made at different values of Rayleigh number Ra in the range 10^{2} ≤ Ra ≤ 10^{5}, for the heat flux H_{t} lying in the range 0.2 ≤ H_{t} ≤ 0.8, enclosure aspect ratio AR within 1.5 ≤ AR ≤ 3.0, center position of a heater Υ_{p} in 0.3 ≤ Υ_{p} ≤ 0.7, solid volume fraction parameter Φ of nanofluids in the range
0% ≤ Φ ≤ 20%, and at the fixed angle φ = 45°. The results show that the maximum value of the local Nusselt number Nu_{Υ} and average Nusselt number Nu can be achieved for the highest Rayleigh number Ra, the smallest center position of the heater Υ_{p}, and the smallest enclosure aspect ratio AR. In addition, it was observed that the enhancement in heat transfer in the trapezoidal enclosure is much improved with increase of the solid volume fraction parameter Φ of nanofluids at a low volume fraction (Φ ≤ 10%), but opposite effects appear when the solid volume fraction parameter
Φ is high (Φ > 10%). Moreover, multiple correlations in terms of the Rayleigh number Ra and the solid volume fraction Φ of nanoparticles have been established.
PB Begell House
LK http://dl.begellhouse.com/journals/46784ef93dddff27,3e8762565fc0c77e,10626ea948fd8865.html