@Article{EE.2020.010433,
AUTHOR = {Cong Qi, Chengchao Wang, Jinghua Tang, Dongtai Han},
TITLE = {Experimental Study on Flow and Heat Transfer Characteristics of Nanofluids  in a Triangular Tube at Different Rotation Angles},
JOURNAL = {Energy Engineering},
VOLUME = {117},
YEAR = {2020},
NUMBER = {2},
PAGES = {63--78},
URL = {http://www.techscience.com/energy/v117n2/38706},
ISSN = {1546-0118},
ABSTRACT = {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°.},
DOI = {10.32604/EE.2020.010433}
}