On the thermally developing forced convection through a porous material under the local thermal non-equilibrium condition: An analytical study

Journal
International journal of heat and mass transfer  
Volume
92
Start Page
815
End Page
823
Citation
International Journal of Heat and Mass Transfer 92 (): 815-823 (2016-01-01)
Publisher DOI
10.1016/j.ijheatmasstransfer.2015.08.091
Scopus ID
2-s2.0-84943382414
The aim of the present analytical study is to investigate a thermally developing forced convective heat transfer inside a channel filled with a porous medium whose walls are imposed to a constant heat flux (i.e. the iso-flux thermal boundary condition). The Darcy's law of motion and the two-energy equation (i.e. local thermal non-equilibrium, LTNE) model are considered. A perturbation analysis is conducted to avoid using any model for the iso-flux thermal boundary condition. Thermally developing forced convection inside a porous-filled channel has previously not been analyzed without implementing a heuristic model for the iso-flux thermal boundary condition. The temperature difference between the fluid and solid phases (called the LTNE intensity) is analytically obtained. Results concerning the LTNE intensity is compared with the available models of the iso-flux thermal boundary condition. In addition, the Nusselt number of a thermally developing convection through a porous material is obtained for the LTNE condition. Also, an expression representing the developing length, i.e. the dimensionless axial location at which the flow becomes fully developed, for a porous-filled channel is proposed for the first time.
Subjects
Analytical study
Iso-flux thermal boundary condition modeling
Local thermal non-equilibrium
Porous medium
Thermally developing forced convection