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Abstract
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Most of previous researches on enhancing the heat transfer rate in pipes and channels have focused on passive
methods. This article introduces near wall active vortex generators (NWAVG) as a strong way to enhance the heat
transfer rate from rectangular channels and simultaneously keep friction losses as low as possible. This article
considers three different motion patterns for NWAVG at a constant Reynolds number of 1000. Also, the impact of
different numbers of vortex generators and different parameters of each motion pattern on the Darcy friction
factor, the Nusselt number and the overall hydrothermal efficiency are examined. The results show that the effect
of vortex generators on the heat transfer rate increases significantly when they approach the channel wall.
Moreover, the results show that the NWAVG can achieve an 185 % increase in the Nusselt number with an
overall hydrothermal efficiency of 1.26.
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