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Convective heat transfer in periodic wavy passages. (English) Zbl 0922.76099

Summary: The rates of heat transfer for flow through a periodic array of wavy passages are studied with an accurate numerical scheme. The flow was observed to be steady until Re around 180 after which self-sustained oscillatory flow was observed. The self-sustained oscillations lead to the destabilization of laminar thermal boundary layers, replenish the near-wall fluid with the fluid in the core region, and thus provide a natural mechanism of heat and mass transfer enhancement. In the steady-flow regime, the average Nusselt numbers for the wavy wall channel were only slightly larger than those for a parallel-plate channel. On the other hand, in the transitional-flow regime, the enhancement of heat transfer was about a factor of 2.5. Friction factors for the wavy channel were about twice those for the parallel-plate channel in the steady-flow region, and remained almost constant in the transitional regime.

MSC:

76D05 Navier-Stokes equations for incompressible viscous fluids
76M20 Finite difference methods applied to problems in fluid mechanics
80A20 Heat and mass transfer, heat flow (MSC2010)
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