A Study Upon Flow and Heat Transfer In Porous Media |

ABSTRACT:

Heat transfer to a fluid passing through a channel filledwith porous materials is the subject of this investigation. It includes thederivation of the temperature solutions in channels having different crosssectional geometries. Primarily, consideration is given to a modified Graetzproblem in parallel plate channels and circular tubes. This presentationincludes numerical features of the exact series solution for these two ductsusing the Brinkman’s model. The results are compared to results from anothernumerical study based on the method of weighted residuals. Moreover, as a testcase, the method of weighted residuals provided flow and heat transfer inelliptical passages. The results include the computation of heat transfer tofluid flowing through elliptical passages with different aspect ratios. Heat transfer through porous media in static saturatedsuperfluid helium is investigated for porous media with different thickness,porosity and pore size. For large pore diameter, data are analyzed with thetortuosity concept in the pure Gorter-Mellink regime. It is shown that thetortuosity is constant over the temperature range investigated. For smaller pore diameter, the analysis reveals that thepermeability is temperature dependent in the Landau regime. In the intermediateregime, a model, including Landau and Gorter-Mellink regime, predicts aconstant tortuosity within 10% but falls short predicting correctly theexperimental data over the entire range of temperature. The study of heat transfer and fluid flow through porousmedia has applications in a variety of engineering fields such as packed beds,perforated plates, tube banks, matrix heat exchangers, regenerators, electroniccomponents etc. The heat transfer coefficients of compact heat exchangersare estimated using transient testing methods. In this paper, numericalmodeling of single blow transient testing method has been used on a porous bodyusing FLUENTTM and then compared with experimental results. The flow frictioncharacteristics were determined experimentally.