Saeid Jani - Academia.edu (original) (raw)
Papers by Saeid Jani
Journal of Enhanced Heat Transfer, 2013
Scientia Iranica, Apr 1, 2004
In this paper, heat and mass transfer phenomena occurring simultaneously in falling lm generator ... more In this paper, heat and mass transfer phenomena occurring simultaneously in falling lm generator of absorption chillers have been studied. The analysis is based on the laminar o w of an Li/Br solution over a horizontal single tube and tube bundle having a constant tube wall temperature. The e ect of boiling has been ignored. An extensive numerical code is provided to calculate the heat transfer coe cient and the rate of evaporation. A parametric study is performed on the coe cient of heat transfer and the evaporation ux of the refrigerant. Dimensionless correlations are obtained to calculate the heat transfer coe cient on the horizontal tube and tube bundle. The comparison between numerical and analytical results with the existing numerical and experimental data verify the validation of the present model.
Magnetohydrodynamic free convection fluid flow and heat transfer in a square cavity filled with a... more Magnetohydrodynamic free convection fluid flow and heat transfer in a square cavity filled with an electric conductive fluid with Prandtl number of 0.7 has been investigated numerically. The horizontal bottom wall of the cavity was kept at Th while the side and the top walls of the cavity were maintained at a constant temperature Tc with Th>Tc. The governing equations written in terms of the primitive variables were solved numerically using the finite volume method while the SIMPLER algorithm was used to couple the velocity and pressure fields. Using the developed code, a parametric study was performed, and the effects of the Rayleigh number and the Hartman number on the fluid flow and heat transfer inside the cavity were investigated. The obtained results showed that temperature distribution and flow pattern inside the cavity depended on both strength of the magnetic field and Rayleigh number. For all cases two counter rotating eddies were formed inside the cavity. The magnetic ...
The natural convection in differentially heated rectangular cavities with a fin attached to the c... more The natural convection in differentially heated rectangular cavities with a fin attached to the cold wall was investigated numerically. The top and the bottom horizontal walls of the cavities were insulated while their left and the right vertical walls were maintained at a constant temperature Th and Tc, respectively with Th > Tc. The governing equations written in terms of the primitive variables were solved numerically using the finite volume method while the velocity and pressure fields were coupled using the SIMPLER algorithm. Using the developed code effects of pertinent parameters such as length and location of fin, aspect ratio of the enclosure, Rayleigh number, and Prandtl number on heat transfer and fluid flow in the enclosure were investigated. The results showed that for the cavity filled with water, at high Rayleigh numbers, a longer fin placing at the middle of the right wall has more remarkable effect on the heat transfer inside the cavity. Also, it was observed tha...
Acta of bioengineering and biomechanics / Wrocław University of Technology, 2010
The objective of this study was to propose a new analytical model for studying response of head i... more The objective of this study was to propose a new analytical model for studying response of head impacts. Head is modeled by fluidfilled ellipsoidal shell of inconstant thickness impacted by a solid elastic sphere. Modeling the head as an ellipsoid is more realistic than modeling it as a sphere, the previous model existing in the literature [3]-[8]. In this model, the effect of Hertzian contact stiffness and local shell stiffness are combined to derive explicit equations for impact duration, the peak force transmitted to head, and the head injury criterion. One of the advantages of the model presented is sensitivity to the site of impact. A comparison between the present analytical results with the analytical data from spherical model [8] has been done to verify the validation of the present model.
Journal of Heat Transfer, 2012
Heat and mass transfer analysis of falling liquid film over a heated horizontal elliptical tube u... more Heat and mass transfer analysis of falling liquid film over a heated horizontal elliptical tube used in desalination systems are investigated. The heat transfer analysis is based on the energy integral formulation with constant wall temperature. Thermal conditions at free surface of the liquid falling film are assumed to be subcooled and saturated, and the effects of surface tension have been considered. The effects of boiling and ripple at the film free surface have been ignored. Heat transfer zoning is considered as the three distinct regions, namely, the jet impingement region, the thermal developing region, and the fully developed region. Extensive analytical study is performed on the thermal hydraulic behavior of the three above mentioned regions, and correlations for both of the film and thermal boundary layer thicknesses, as well as the local and average heat transfer coefficients, have been derived. The results show that the effects of surface tension on heat transfer coeffi...
Journal of Enhanced Heat Transfer, 2013
Acta of bioengineering and biomechanics / Wrocław University of Technology, 2010
The objective of this study was to propose a new analytical model for studying response of head i... more The objective of this study was to propose a new analytical model for studying response of head impacts. Head is modeled by fluidfilled ellipsoidal shell of inconstant thickness impacted by a solid elastic sphere. Modeling the head as an ellipsoid is more realistic than modeling it as a sphere, the previous model existing in the literature [3]-[8]. In this model, the effect of Hertzian contact stiffness and local shell stiffness are combined to derive explicit equations for impact duration, the peak force transmitted to head, and the head injury criterion. One of the advantages of the model presented is sensitivity to the site of impact. A comparison between the present analytical results with the analytical data from spherical model [8] has been done to verify the validation of the present model.
Advanced Energy Systems, 2002
Heat Transfer Research, 2011
Fluid flow and natural convection heat transfer in a differentially heated square cavity with a f... more Fluid flow and natural convection heat transfer in a differentially heated square cavity with a fin attached to its cold wall is investigated numerically. The top and the bottom horizontal walls of the cavity are insulated while the left and right vertical walls of the cavity are maintained at a constant temperature T h and T c , with T h > T c , respectively. The governing equations written in terms of the primitive variables are solved numerically using the finite volume method and the SIMPLER algorithm. Using the developed code, a parametric study is performed, and the effects of the Rayleigh number, length of the fin and its position on the flow pattern and heat transfer inside the enclosure are investigated. The results show that for high Rayleigh numbers, a longer fin placing at the middle of the right wall has a more remarkable effect on the flow field and heat transfer inside the cavity.
Heat Transfer Research, 2014
Free convection heat transfer in rectangular enclosures fi lled with Al 2 O 3-water nanofl uid is... more Free convection heat transfer in rectangular enclosures fi lled with Al 2 O 3-water nanofl uid is investigated numerically, and the eff ects of suspended nanoparticles of diff erent diameters are considered. The governing equations in terms of primitive variables are discretized numerically using the fi nite volume method and SIMPLER algorithm. The results were obtained for width range of the Rayleigh number, nanoparticles volume fraction and aspect ratio of cavity. Also nanoparticles with two different diameters, namely 36 nm and 47 nm have been chosen. The obtained results showed that for the square enclosure utilizing the suspended nanoparticles with both considered diameters the rate of heat transfer increased only at Ra = 10 3 that conduction dominated the heat transfer process, while at other Rayleigh numbers, a deterioration on average Nusselt number was observed.
Heat Transfer Research, 2014
Free convection heat transfer in rectangular enclosures fi lled with Al 2 O 3-water nanofl uid is... more Free convection heat transfer in rectangular enclosures fi lled with Al 2 O 3-water nanofl uid is investigated numerically, and the eff ects of suspended nanoparticles of diff erent diameters are considered. The governing equations in terms of primitive variables are discretized numerically using the fi nite volume method and SIMPLER algorithm. The results were obtained for width range of the Rayleigh number, nanoparticles volume fraction and aspect ratio of cavity. Also nanoparticles with two different diameters, namely 36 nm and 47 nm have been chosen. The obtained results showed that for the square enclosure utilizing the suspended nanoparticles with both considered diameters the rate of heat transfer increased only at Ra = 10 3 that conduction dominated the heat transfer process, while at other Rayleigh numbers, a deterioration on average Nusselt number was observed.
Journal of Enhanced Heat Transfer, 2013
Scientia Iranica, Apr 1, 2004
In this paper, heat and mass transfer phenomena occurring simultaneously in falling lm generator ... more In this paper, heat and mass transfer phenomena occurring simultaneously in falling lm generator of absorption chillers have been studied. The analysis is based on the laminar o w of an Li/Br solution over a horizontal single tube and tube bundle having a constant tube wall temperature. The e ect of boiling has been ignored. An extensive numerical code is provided to calculate the heat transfer coe cient and the rate of evaporation. A parametric study is performed on the coe cient of heat transfer and the evaporation ux of the refrigerant. Dimensionless correlations are obtained to calculate the heat transfer coe cient on the horizontal tube and tube bundle. The comparison between numerical and analytical results with the existing numerical and experimental data verify the validation of the present model.
Magnetohydrodynamic free convection fluid flow and heat transfer in a square cavity filled with a... more Magnetohydrodynamic free convection fluid flow and heat transfer in a square cavity filled with an electric conductive fluid with Prandtl number of 0.7 has been investigated numerically. The horizontal bottom wall of the cavity was kept at Th while the side and the top walls of the cavity were maintained at a constant temperature Tc with Th>Tc. The governing equations written in terms of the primitive variables were solved numerically using the finite volume method while the SIMPLER algorithm was used to couple the velocity and pressure fields. Using the developed code, a parametric study was performed, and the effects of the Rayleigh number and the Hartman number on the fluid flow and heat transfer inside the cavity were investigated. The obtained results showed that temperature distribution and flow pattern inside the cavity depended on both strength of the magnetic field and Rayleigh number. For all cases two counter rotating eddies were formed inside the cavity. The magnetic ...
The natural convection in differentially heated rectangular cavities with a fin attached to the c... more The natural convection in differentially heated rectangular cavities with a fin attached to the cold wall was investigated numerically. The top and the bottom horizontal walls of the cavities were insulated while their left and the right vertical walls were maintained at a constant temperature Th and Tc, respectively with Th > Tc. The governing equations written in terms of the primitive variables were solved numerically using the finite volume method while the velocity and pressure fields were coupled using the SIMPLER algorithm. Using the developed code effects of pertinent parameters such as length and location of fin, aspect ratio of the enclosure, Rayleigh number, and Prandtl number on heat transfer and fluid flow in the enclosure were investigated. The results showed that for the cavity filled with water, at high Rayleigh numbers, a longer fin placing at the middle of the right wall has more remarkable effect on the heat transfer inside the cavity. Also, it was observed tha...
Acta of bioengineering and biomechanics / Wrocław University of Technology, 2010
The objective of this study was to propose a new analytical model for studying response of head i... more The objective of this study was to propose a new analytical model for studying response of head impacts. Head is modeled by fluidfilled ellipsoidal shell of inconstant thickness impacted by a solid elastic sphere. Modeling the head as an ellipsoid is more realistic than modeling it as a sphere, the previous model existing in the literature [3]-[8]. In this model, the effect of Hertzian contact stiffness and local shell stiffness are combined to derive explicit equations for impact duration, the peak force transmitted to head, and the head injury criterion. One of the advantages of the model presented is sensitivity to the site of impact. A comparison between the present analytical results with the analytical data from spherical model [8] has been done to verify the validation of the present model.
Journal of Heat Transfer, 2012
Heat and mass transfer analysis of falling liquid film over a heated horizontal elliptical tube u... more Heat and mass transfer analysis of falling liquid film over a heated horizontal elliptical tube used in desalination systems are investigated. The heat transfer analysis is based on the energy integral formulation with constant wall temperature. Thermal conditions at free surface of the liquid falling film are assumed to be subcooled and saturated, and the effects of surface tension have been considered. The effects of boiling and ripple at the film free surface have been ignored. Heat transfer zoning is considered as the three distinct regions, namely, the jet impingement region, the thermal developing region, and the fully developed region. Extensive analytical study is performed on the thermal hydraulic behavior of the three above mentioned regions, and correlations for both of the film and thermal boundary layer thicknesses, as well as the local and average heat transfer coefficients, have been derived. The results show that the effects of surface tension on heat transfer coeffi...
Journal of Enhanced Heat Transfer, 2013
Acta of bioengineering and biomechanics / Wrocław University of Technology, 2010
The objective of this study was to propose a new analytical model for studying response of head i... more The objective of this study was to propose a new analytical model for studying response of head impacts. Head is modeled by fluidfilled ellipsoidal shell of inconstant thickness impacted by a solid elastic sphere. Modeling the head as an ellipsoid is more realistic than modeling it as a sphere, the previous model existing in the literature [3]-[8]. In this model, the effect of Hertzian contact stiffness and local shell stiffness are combined to derive explicit equations for impact duration, the peak force transmitted to head, and the head injury criterion. One of the advantages of the model presented is sensitivity to the site of impact. A comparison between the present analytical results with the analytical data from spherical model [8] has been done to verify the validation of the present model.
Advanced Energy Systems, 2002
Heat Transfer Research, 2011
Fluid flow and natural convection heat transfer in a differentially heated square cavity with a f... more Fluid flow and natural convection heat transfer in a differentially heated square cavity with a fin attached to its cold wall is investigated numerically. The top and the bottom horizontal walls of the cavity are insulated while the left and right vertical walls of the cavity are maintained at a constant temperature T h and T c , with T h > T c , respectively. The governing equations written in terms of the primitive variables are solved numerically using the finite volume method and the SIMPLER algorithm. Using the developed code, a parametric study is performed, and the effects of the Rayleigh number, length of the fin and its position on the flow pattern and heat transfer inside the enclosure are investigated. The results show that for high Rayleigh numbers, a longer fin placing at the middle of the right wall has a more remarkable effect on the flow field and heat transfer inside the cavity.
Heat Transfer Research, 2014
Free convection heat transfer in rectangular enclosures fi lled with Al 2 O 3-water nanofl uid is... more Free convection heat transfer in rectangular enclosures fi lled with Al 2 O 3-water nanofl uid is investigated numerically, and the eff ects of suspended nanoparticles of diff erent diameters are considered. The governing equations in terms of primitive variables are discretized numerically using the fi nite volume method and SIMPLER algorithm. The results were obtained for width range of the Rayleigh number, nanoparticles volume fraction and aspect ratio of cavity. Also nanoparticles with two different diameters, namely 36 nm and 47 nm have been chosen. The obtained results showed that for the square enclosure utilizing the suspended nanoparticles with both considered diameters the rate of heat transfer increased only at Ra = 10 3 that conduction dominated the heat transfer process, while at other Rayleigh numbers, a deterioration on average Nusselt number was observed.
Heat Transfer Research, 2014
Free convection heat transfer in rectangular enclosures fi lled with Al 2 O 3-water nanofl uid is... more Free convection heat transfer in rectangular enclosures fi lled with Al 2 O 3-water nanofl uid is investigated numerically, and the eff ects of suspended nanoparticles of diff erent diameters are considered. The governing equations in terms of primitive variables are discretized numerically using the fi nite volume method and SIMPLER algorithm. The results were obtained for width range of the Rayleigh number, nanoparticles volume fraction and aspect ratio of cavity. Also nanoparticles with two different diameters, namely 36 nm and 47 nm have been chosen. The obtained results showed that for the square enclosure utilizing the suspended nanoparticles with both considered diameters the rate of heat transfer increased only at Ra = 10 3 that conduction dominated the heat transfer process, while at other Rayleigh numbers, a deterioration on average Nusselt number was observed.