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ISSN Druckformat: 1091-028X
ISSN Online: 1934-0508
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TRANSIENT BEHAVIOR OF MICROPOLAR FLUIDS THROUGH A POROUS WAVY CHANNEL
ABSTRAKT
The transient heat convection phenomena of micropolar fluids flowing through wavy channels with porous media are numerically analyzed by using the coordinate transformation and the spline alternating-direction implicit method. Numerical results considering the material characteristics of micropolar fluids and comparing with Newtonian fluid are discussed in detail Calculations are performed on a personal computer by using the Spline Alternating-Direction Implicit method, which applies the theory of coordinate transformation and transforms complex curves into flat surfaces. The governing equations after nondimensional transformation are expressed with stream function, vortex function, angular momentum and temperature function, and the transient heat transfer effect is determined to discuss transient heat convection of micropolar fluid in vertical wavy channels saturated with porous media. The results indicate that the micropolar fluids have higher flow resistance but lower heat transfer rates. As the wavy surface is lumpy, the displacement of boundary causes the flow field to change and further affects the heat transfer rate. A higher Ri value indicates a more apparent buoyancy effect, reduced recirculation flow in the trough region and increased velocity gradient at the surface, thereby leading to a higher Nusselt number and heat transfer rate. In the case of lower Darcy number flow, the porous media provide a higher heat transfer rate than a single phase flow.