Convective flow through a vertical channel is relevant to many industrial and domestic applications. Examples include thermal flows between panel radiators and through wall-integrated solar chimney for building ventilation. In this work, we examine the effects of flow blockage on heat and mass transfer of convective flow through a vertical channel under various configurations including isothermal and isoflux heating, one-wall and two-wall heating, and with different bluff bodies (a circular cylinder or a louvre) placed in the channel. Numerical simulations are carried out over a range of Rayleigh numbers, blockage ratios, and blockage locations.
It is found that the presence of a bluff body in the convective flow channel significantly enhances mixing and turbulence and in turn enhances the convective flow through the channel. In the case with a rigidly mounted circular cylinder in the channel, three distinct wake flow regimes are observed for both isothermal and isoflux heating at different Rayleigh numbers and blockage ratios, including steady symmetric, unsteady periodic, and unsteady asymmetric flow regimes. For the two-wall isothermal heating case, greater than 60% heat transfer enhancement relative to an unblocked channel may be achieved in the unsteady periodic flow regime at certain configuration. For the two-wall isoflux heating case, up to 40% enhancement of the mass flow rate and up to 31% drop of the averaged wall temperature may be achieved. And for the one-wall isoflux heating case, the presence of a louvre in the channel may lead to more than double the ventilation rate of an unblocked channel.
The present investigation has demonstrated an effective passive strategy using flow blockage to enhance thermal and ventilation performance of convective flow through vertical channels.

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