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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Numerical Study of Heat Transfer Enhancement with Porous Heat Sink in the Pulsating Channel Flow

Hsu, Kao-Wei 19 July 2002 (has links)
A numerical study was carried out for enhanced heat transfer from two heated blocks in a pulsating channel flow by porous heat sink. The flow over the fluid region is governed by the Navier-Stokes equation, and the flow through the porous medium is governed by the Darcy-Brinkman-Forchheimer equation. These two flows are coupled through the interface boundary conditions at the porous/fluid and porous/solid interfaces. After a stream function-vorticity transformation, solution of the coupled governing equations for fluid/porous/solid composite system is obtained using the control-volume-based procedure and hybrid scheme. Comprehensive time-dependent flow and temperature data obtained and averaged over a cycle of pulsation in a periodic steady state. In addition, this study details the effects of variation in the governing parameters, such as inertia parameter, Dracy number, Reynolds number, Strouhal number, pulsation amplitude and geometric parameters, to illustrate important fundamental and practical results. The results show that the periodic change of shape of interblock recirculation flow caused by porous-covering blocks has significant enhanced effect on flow pattern and heat transfer characteristics. This enhanced effect is found to increase with Reynolds number, Strouhal number and pulsation amplitude but decrease with Dracy number. In comparison with the non-porous heat sink case for a steady non-pulsating flow, significant increases in the average Nusselt number are predicted and the instantaneous maximum temperatures within the heated block array are reduced. Moreover, it is shown that specific choices in certain geometric parameters, such as interblock space, can make pronounded change in the cooling of heated block.

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