Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 53 Issue 3 (Special Issue) 2021 05 22 Numerical simulation of nanofluid flow in an annulus with porous baffles based on combination of Darcy-Brinkman-Forchheimer model and two-phase mixture model Numerical simulation of nanofluid flow in an annulus with porous baffles based on combination of Darcy-Brinkman-Forchheimer model and two-phase mixture model 1897 1914 3868 10.22060/mej.2020.16065.6276 FA Hosein Namadchian Islamic Azad University of Mashhad Iman Zahmatkesh Department of Mechanical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran Seyed Mahmood Abulhasan Alavi Islamic Azad University of Mashhad Journal Article 2019 04 14 In this paper, forced convection heat transfer of a nanofluid in an annulus with porous baffles on the inner and outer walls is investigated numerically. The nanofluid is simulated based on the two-phase mixture model while the flow in the porous region is described by the Darcy-Brinkman-Forchheimer model. The fluid flow is considered laminar, steady, axisymmetric, and incompressible. The governing equations have been solved using the finite volume method. The effect of parameters such as the Darcy number, the height of the porous baffles, the thermal conductivity ratio, and the volume fraction, and the type of the nanoparticles on the flow field, heat transfer, and pressure drop have been investigated. The results show that the use of the porous baffles in the flow path leads to significant variations in the characteristics of the flow and heat transfer. Reducing the Darcy and Reynolds numbers leads to the formation of vortices behind the baffles that has a significant impact on the heat transfer. By decreasing the Darcy number, the heat transfer increases substantially. This also causes a severe pressure drop in the flow. Increasing the thermal conductivity ratio raises the local Nusslet number at the wall near the baffles, which is more remarkable in higher values of permeability. Increasing the height of the porous baffles reduces the thickness of the boundary layer and enhances heat transfer. In this paper, forced convection heat transfer of a nanofluid in an annulus with porous baffles on the inner and outer walls is investigated numerically. The nanofluid is simulated based on the two-phase mixture model while the flow in the porous region is described by the Darcy-Brinkman-Forchheimer model. The fluid flow is considered laminar, steady, axisymmetric, and incompressible. The governing equations have been solved using the finite volume method. The effect of parameters such as the Darcy number, the height of the porous baffles, the thermal conductivity ratio, and the volume fraction, and the type of the nanoparticles on the flow field, heat transfer, and pressure drop have been investigated. The results show that the use of the porous baffles in the flow path leads to significant variations in the characteristics of the flow and heat transfer. Reducing the Darcy and Reynolds numbers leads to the formation of vortices behind the baffles that has a significant impact on the heat transfer. By decreasing the Darcy number, the heat transfer increases substantially. This also causes a severe pressure drop in the flow. Increasing the thermal conductivity ratio raises the local Nusslet number at the wall near the baffles, which is more remarkable in higher values of permeability. Increasing the height of the porous baffles reduces the thickness of the boundary layer and enhances heat transfer. https://mej.aut.ac.ir/article_3868_70162fe655ec381ac6312ebf026aac54.pdf