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Conjugate local thermal nonequilibrium and non-Darcy flow inside porous enclosure: Analysis of localized heating and cooling arrangements
Authors:Omar Rafae Alomar  Noor Moneer Basher  Anwar Ahmed Yousif  Qais Abid Yousif
Affiliation:Engineering Technical College of Mosul, Northern Technical University, Mosul, Iraq
Abstract:This study covers a simulation on conjugate free convective in a porous enclosure containing a side wall thickness and partially heated and cooled from sides under the considerations of local thermal nonequilibrium (LTNE) and non-Darcy flow. Interest has been focused on how the side wall thickness and the locations of cooled and heated parts affect the effectiveness of the Nusselt number (Nu). Three different cases of localized heating and cooling locations have been implemented for the following ranges: scaled heat transfer coefficient ( 0.1 H 100 $0.1\le H\le 100$ ), wall to fluid thermal conductivity ratio ( 0.1 R k 100 $0.1{\le R}_{k}\le 100$ ), modified Rayleigh number ( 200 Ra * 1000 $200\le {Ra}* \le 1000$ ), wall width ( 0.1 Z ? 0.5 $0.1\le \hat{Z}\le 0.5$ ), inertial parameter ( 10 ? 4 F s / P r * 10 ? 2 ${10}^{-4}{\le F}_{s}/{P}_{r}^{* }\le {10}^{-2}$ ), and thermal conductivity ratio ( 0.1 K r 100 $0.1\le {K}_{r}\le 100$ ). Outcomes show that Z ? $\hat{Z}$ and the locations of cooled and heated parts have remarkable impacts on all the Nusselt numbers. The intensity of LTNE region considerably relies on Ra * ${Ra}{* }$ , K r ${K}_{r}$ and H $H$ . The total average NuT is highly dependent on R k ${R}_{k}$ , Ra * ${Ra}{* }$ , Z ? $\hat{Z}$ , F s / P r * ${F}_{s}/{P}_{r}^{* }$ , and K r ${K}_{r}$ as compared to H. The increase in Z ? $\hat{Z}$ leads to change of the convective mechanism to conductive mode. The rise in R k ${R}_{k}$ guides to increase Nu, where R k ${R}_{k}$ can control the flow strength. The actions of F s / P r * ${F}_{s}/{P}_{r}^{* }$ on Nuf is more evident than Nus. For low H and Kr, the size of LTNE zone is considerably affected by H as compared to Kr although Kr has a high influence on Nu. For high Kr and H, the LTNE zone has closely vanished. Findings display that the Case 2 provided the highest Nu for all tested parameters except the case of K r = 0.1 ${K}_{r}=0.1$ . Finally, it is evident that for the problems that employed solid conduction wall with localized heating and cooling sections, Case 2 is recommended for future use in the applications that implement a porous medium and depend on free convection.
Keywords:conjugate free convection  locations of heating and cooling parts  non-Darcian flow  partially heated and cooled  porous cavity  wall LTNE model
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