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Flow pulsation and baffle’s effects on the opposing mixed convection in a vertical channel. (English) Zbl 1188.76247
Summary: This numerical study aims to investigate the effects of a horizontal baffle on the heat transfer characteristics of pulsating opposing mixed convection in a parallel vertical open channel. The influences of the dimensionless pulsating frequency Strouhal number and magnitude $$A$$, Prandtl number and baffle position $$L_{b}$$ on the velocity and temperature distribution and long-time average Nusselt number $$\langle \overline {Nu}\rangle$$ variation for the system at various $$Re$$ and $$Gr/Re^{2}$$ are explored in detail. Our results show that the channel with both flow pulsation and a baffle gives the best heat transfer. With a larger $$Re$$, the inlet flow pulsation dominates the whole velocity field in the channel. $$\langle \overline {Nu}\rangle$$ always increases with a larger $$Re$$, pulsation magnitude $$A$$ and Prandtl number. Maximum $$\langle \overline {Nu}\rangle$$ occurs at some specific imposed pulsating frequencies which can be considered to be the natural frequency of the system.

##### MSC:
 76R05 Forced convection 76R10 Free convection 76M20 Finite difference methods applied to problems in fluid mechanics 80A20 Heat and mass transfer, heat flow (MSC2010)
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