TY - JOUR
T1 - Hydrodynamically and thermally developing flow in a rectangular channel filled with a high porosity fiber and rotating about a parallel axis
AU - Alhusseny, Ahmed Niameh Mehdy
AU - Turan, Ali
AU - Nasser, Adel
AU - Hidri, Faiza
PY - 2015/8/5
Y1 - 2015/8/5
N2 - Rotating machineries operating at extreme temperature conditions usually need to be cooled internally by involving cooling passages inside them. A potential way to improve heat dissipated by these channels is by filling them with high porosity metal foams ε≥0.89. This proposal is examined numerically by studying developing convective flow across a porous rectangular channel subjected to a uniform wall heat flux and rotating in a parallel-mode. In regards to the influence of rotation, both centrifugal buoyancy and Coriolis forces are considered. The generalised model is used to mathematically simulate the momentum equations employing the Boussinesq approximation for the density variation. Moreover, thermal dispersion has been taken into account with considering that fluid and solid phases are in a local thermal non-equilibrium. Computations are performed for a wide range of dimensionless parameters including the aspect ratio, medium porosity, fiber size, rotation number, and solid to fluid-phase thermal conductivity ratio, while the values of Reynolds and Prandtl numbers are maintained constant. The results reveal that both rotation and thermal dispersion have significant roles in enhancing heat transfer at high levels of porosity and low conductivity ratios. However, these roles are reduced gradually with decreasing the medium porosity or increasing thermal conductivity ratio, but do not completely vanish. In addition, overall performance is improved with either decreasing the aspect ratio for Ar1. Eventually, the worth of using high porosity fibers in enhancing the heat transported through rotating channels has been inspected. An overall enhancement parameter was compared for the current study with a previous study regarding turbulent flow in a rotating clear channel, where it has been confirmed that the current proposal is practically justified and efficient.
AB - Rotating machineries operating at extreme temperature conditions usually need to be cooled internally by involving cooling passages inside them. A potential way to improve heat dissipated by these channels is by filling them with high porosity metal foams ε≥0.89. This proposal is examined numerically by studying developing convective flow across a porous rectangular channel subjected to a uniform wall heat flux and rotating in a parallel-mode. In regards to the influence of rotation, both centrifugal buoyancy and Coriolis forces are considered. The generalised model is used to mathematically simulate the momentum equations employing the Boussinesq approximation for the density variation. Moreover, thermal dispersion has been taken into account with considering that fluid and solid phases are in a local thermal non-equilibrium. Computations are performed for a wide range of dimensionless parameters including the aspect ratio, medium porosity, fiber size, rotation number, and solid to fluid-phase thermal conductivity ratio, while the values of Reynolds and Prandtl numbers are maintained constant. The results reveal that both rotation and thermal dispersion have significant roles in enhancing heat transfer at high levels of porosity and low conductivity ratios. However, these roles are reduced gradually with decreasing the medium porosity or increasing thermal conductivity ratio, but do not completely vanish. In addition, overall performance is improved with either decreasing the aspect ratio for Ar1. Eventually, the worth of using high porosity fibers in enhancing the heat transported through rotating channels has been inspected. An overall enhancement parameter was compared for the current study with a previous study regarding turbulent flow in a rotating clear channel, where it has been confirmed that the current proposal is practically justified and efficient.
KW - High porosity fiber
KW - Rotation
KW - Channel flow
KW - Thermal dspersion
KW - Aspect ratio
U2 - 10.1016/j.icheatmasstransfer.2015.07.012
DO - 10.1016/j.icheatmasstransfer.2015.07.012
M3 - Article
SN - 0735-1933
VL - 67
SP - 114
EP - 123
JO - International Communications in Heat and Mass Transfer
JF - International Communications in Heat and Mass Transfer
ER -