TY - EJOU
AU - Qi, Cong
AU - Wang, Chengchao
AU - Tang, Jinghua
AU - Han, Dongtai
TI - Experimental Study on Flow and Heat Transfer Characteristics of Nanofluids in a Triangular Tube at Different Rotation Angles
T2 - Energy Engineering
PY - 2020
VL - 117
IS - 2
SN - 1546-0118
AB - Because of the poor thermal performance of ordinary tubes, a
triangular tube was used to replace the smooth channel in the heat transfer
system, and nanofluids were used to take the place of ordinary fluids as the heat
transfer medium. High stability nanofluids were prepared, and an experimental
set on flow and heat exchange was established. Effects of triangular tube rotation
angles (α = 0°, 30°, 60°) as well as mass fractions of nanofluids (ω = 0.1%, 0.3%,
0.5%) on heat exchange and flow performance were experimentally considered
at Reynolds numbers (Re = 800–8000). It was shown that the triangular tube
with a rotation angle α = 0° possesses the most excellent thermal property,
followed by a rotation angle α = 60° triangular tube, and a rotation angle α = 30° triangular tube has the worst heat exchange property. Results also revealed that
resistance coefficients of the triangular tube with rotation angles α = 0° and α =
30° are close to each other, and a rotation angle α = 60° triangular tube shows the
minimal resistance coefficient. It could be also seen that higher nanoparticle
mass fraction can augment the thermal performance. However, higher
nanoparticle mass fraction can also lead to an increment in resistance coefficient. A comprehensive performance evaluation index was introduced to appraise the
augment in Nusselt number and flow resistance coefficient. The experiment
revealed that the highest index emerges with nanofluids (ω = 0.5%) in the
triangular tube with a rotation angle α = 0°.
KW - Nanofluids; forced convection; heat transfer enhancement; triangular tube; rotation angle
DO - 10.32604/EE.2020.010433