TY - JOUR
T1 - Turbulent Flows inside Pipes Equipped with Novel Perforated V-shaped Rectangular Winglet Turbulators
T2 - Numerical Simulations
AU - Erfanian Nakhchi Toosi, Mahdi
AU - Rahmati, Mohammad
PY - 2020/11/1
Y1 - 2020/11/1
N2 - In this study, computational simulations have been performed to investigate the turbulent characteristics and energy consumption through heat exchanger tubes equipped by new perforated V-shaped rectangular winglet (PVRW) turbulators. The effects of the holes intensity on the velocity and temperature contours are additionally investigated. The Reynolds number, hole diameter ratio, and the number of holes are selected is in the range of 5000 ≤ ≤ 18000, 0 ≤ ≤ 0.40, and 0 ≤ ≤ 14, respectively. (RNG) k-ε turbulent model which is a finite volume solver is utilized for the CFD simulation. It was noticed that the proposed perforated turbulators could considerably intensify the thermal performance compared to typical VRW inserts. It is found that the recirculating flow generated by the PVRW, augments the fluid mixing and transfers the heat from the pipe walls to the core of the tube. The simulations illustrate that the amount of heat transfer enhances 25.2% with reducing the DR from 0.4 to 0.13 at Re=18000 and N=14. Also, using PVRW turbulators with N=7, DR=0.26 augments the average Nusselt number around 354.3% compared to the circular pipe without inserts. The highest thermal efficiency parameter of n=2.25 could be obtained at Re=5000 for the heat exchangers fitted by vortex generators with N=14 and DR=0.26.
AB - In this study, computational simulations have been performed to investigate the turbulent characteristics and energy consumption through heat exchanger tubes equipped by new perforated V-shaped rectangular winglet (PVRW) turbulators. The effects of the holes intensity on the velocity and temperature contours are additionally investigated. The Reynolds number, hole diameter ratio, and the number of holes are selected is in the range of 5000 ≤ ≤ 18000, 0 ≤ ≤ 0.40, and 0 ≤ ≤ 14, respectively. (RNG) k-ε turbulent model which is a finite volume solver is utilized for the CFD simulation. It was noticed that the proposed perforated turbulators could considerably intensify the thermal performance compared to typical VRW inserts. It is found that the recirculating flow generated by the PVRW, augments the fluid mixing and transfers the heat from the pipe walls to the core of the tube. The simulations illustrate that the amount of heat transfer enhances 25.2% with reducing the DR from 0.4 to 0.13 at Re=18000 and N=14. Also, using PVRW turbulators with N=7, DR=0.26 augments the average Nusselt number around 354.3% compared to the circular pipe without inserts. The highest thermal efficiency parameter of n=2.25 could be obtained at Re=5000 for the heat exchangers fitted by vortex generators with N=14 and DR=0.26.
KW - Turbulent flow
KW - CFD
KW - Perforated vortex generator
KW - Rectangular winglet
KW - Heat transfer augmentation
U2 - 10.1115/1.4047319
DO - 10.1115/1.4047319
M3 - Article
SN - 0195-0738
VL - 142
JO - Journal of Energy Resources Technology, Transactions of the ASME
JF - Journal of Energy Resources Technology, Transactions of the ASME
IS - 11
M1 - 112106
ER -