abdelaziz nasr - Academia.edu (original) (raw)

Papers by abdelaziz nasr

Current Applied Physics, Mar 1, 2016

We present a self-consistent calculation combined with the 16-band anticrossing model in order to... more We present a self-consistent calculation combined with the 16-band anticrossing model in order to investigate the electronic and optical properties of n-doped GaNAsBi/GaAs multiple-QWs operating at 1.55 µm. Optoelectronic features of these quantum structures seem advantageous for the design of photodetector devices. We have found that doping induces a blue shift of the fundamental transition energy for the uncoupled double-QWs with the barrier width L b = 12 nm. This transition energy shows a red shift when the doped DQWs are coupled (L b = 2 nm). An applied electric field favors further this shift. The coupling and Stark effects on the spatial distribution of confined electrons density are discussed. The absorption coefficient for the coupled 4 nm GaN .04 As .89 Bi .07 /GaAs DQWs is enhanced compared to the un-doped or uncoupled DQWs. Finally, we have examined the dependence of the absorption magnitude on the doping density and electric field for different values of wells number.

Journal of Alloys and Compounds, 2015

By applying the band anticrossing model combined with the envelope function formalism, a theoreti... more By applying the band anticrossing model combined with the envelope function formalism, a theoretical study of optoelectronic properties of lattice matched GaNAsBi-based multiple quantum wells (MQWs) operating at 1.55 μm was performed. Indeed, the electronic band structure of 4.5 nm GaN.04As.89Bi.07/GaAs double quantum wells (DQWs) was computed for a barrier width (Lb) varying from 1 to 12 nm. We found that the coupling between GaNAsBi wells which occurs for Lb ≤ 8 nm, modifies the confined energies levels and the fundamental interband transition of the coupled GaNAsBi/GaAs DQWs. This produces a slight shift of the wavelength emission from 1.55 μm. We have also discussed the coupling effect on the in-plane carrier effective mass and the optical absorption spectra of these DQWs. Basing on the enhancement of electron mobility and the slight amelioration of absorption peak magnitude brought by the well coupling, we have chosen the GaN.04As.89Bi.07/GaAs DQWs with Lb = 3.5 nm and Lw modified to 4.3 nm as a candidate for optoelectronic devices operating exactly at 1.55 μm. Finally, we are focused on the investigation of the optical properties of 7(GaAs)3.56(GaN.04As.89Bi.07)4.1 superlattices (SLs) operating at 1.55 μm especially the absorption coefficient behavior.

Semiconductors, 2015

Band structures of GaN 0.58y As 1-1.58y Bi y /GaAs quantum wells (QWs) were studied using the ban... more Band structures of GaN 0.58y As 1-1.58y Bi y /GaAs quantum wells (QWs) were studied using the band anticrossing model and the envelope function approximation. The confined states energies and the oscillator strengths of interband transitions were determined for well widths L W and Bi composition y varying in the range of 4-10 nm and 0-0.07 respectively. The emissions 1.3 and 1.55 µm were reached for specific couples (L W , y). The band anticrossing effect on the in plane carriers effective mass has been investigated at k = 0. The absorbance spectra were calculated for QWs operating at 1.3 and 1.55 µm.

Infrared Physics & Technology, 2014

h i g h l i g h t s GaAs 1Àx Bi x band structures have been calculated using Valence-BAC models. ... more h i g h l i g h t s GaAs 1Àx Bi x band structures have been calculated using Valence-BAC models. Reduction of E g by 81 meV/%Bi accompanied by an increase of D so+ by 56 meV/%Bi. A crossover at 0.73 eV has occurred between E g and D so+ for GaAs .88 Bi .12. Bismuth composition dependence on effective mass was discussed. Intrinsic carrier density increases with both Bi composition and temperature.

Materials Science in Semiconductor Processing, 2014

Band structures of n-i doped lattice-matched GaNAsBi/GaAs quantum wells are studied theoretically... more Band structures of n-i doped lattice-matched GaNAsBi/GaAs quantum wells are studied theoretically using a self-consistent calculation (based on the envelop function formalism) combined with the 16-band anti-crossing model. Operating at 1.55 μm, these QWs can represent active zones of temperature-insensitive optoelectronic device applications intended for optical fiber communications. We have calculated physical parameters of the structures such as the confining potential profiles, the Fermi level, the subband energies and their corresponding wavefunctions as well as the oscillator strength of interband transitions, the subband occupations, and the confined electrons density distributions. Finally, the absorption coefficient spectra of GaNAsBi-based QWs are also computed.

Infrared Physics & Technology, 2013

h i g h l i g h t s GaNAsBi band structures have been calculated using BAC model and k Á p method... more h i g h l i g h t s GaNAsBi band structures have been calculated using BAC model and k Á p method. Band-gap energy of GaNAsBi lattice matched to GaAs decreases by 198 meV/%Bi. Spin-orbit splitting increases by 56 meV/%Bi regardless N content. A crossover at about 0.6 eV has occurred between E g and D so of GaN .039 As .893 Bi .068. Effective masses behaviors of carriers have been discussed at C point.

Frontiers in Mechanical Engineering

The ammonia-water film condensation is used as an efficient working fluid in industrial applicati... more The ammonia-water film condensation is used as an efficient working fluid in industrial applications such as refrigeration, plate condenser and evaporator, absorber/generator heat exchange, air-conditioning, heat pumps and separation processes. The present work focuses on a numerical investigation of water-ammonia condensation on a falling binary liquid film inside a parallel plate condenser by mixed convection. The parallel plate condenser is composed by two parallel vertical plates. One of the plates is wetted by liquidfilm and cooled by the thermal flux cooling while the other plate is isothermal and dry. Parametric computations were performed to investigate the effects of the inlet parameters of gas, the properties of the binary liquid film as well as the thermal flux cooling on the combined mass and heat transfer and on the efficiency of the parallel plate condenser. The results show that an increase in the inlet vapor of ammonia as well as of vapor water enhances the efficienc...

The ammonia-water film condensation is used as an efficient working fluid in industrial applicati... more The ammonia-water film condensation is used as an efficient working fluid in industrial applications such as refrigeration, plate condenser and evaporator, absorber/generator heat exchange, airconditioning , heat pumps and separation processes. The present work focuses on a numerical investigation of water-ammonia condensation on a falling binary liquid film inside a parallel plate condenser by mixed convection. The parallel plate condenser is composed by two parallel vertical plates. One of the plates is wetted by liquidfilm and cooled by the thermal flux cooling while the other plate is isothermal and dry. Parametric computations were performed to investigate the effects of the inlet parameters of gas, the properties of the binary liquid film as well as the thermal flux cooling on the combined mass and heat transfer and on the efficiency of the parallel plate condenser. The results show that an increase in the inlet vapor of ammonia as well as of vapor water enhances the efficiency of the parallel plate condenser. It is shown also that an enhancement of efficiency of the parallel plate condenser has been recorded when the thermal flux cooling and inlet liquid flow rate is elevated. Whereas the increase of the inlet liquid concentration of ammonia inhibits the efficiency of the parallel plate condenser.

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

A fractional model was developed for presenting the thermal assessment of nanoparticles in an inc... more A fractional model was developed for presenting the thermal assessment of nanoparticles in an inclined moving surface. Water was used as a base fluid, while the nanofluid utilized copper oxide and silver nanoparticles. The modification of the thermal model was further supported by mixed convection, magnetic force, and porous saturated space. Slip effects to the porous surface were also introduced. The fluctuation in temperature at different times was assumed by following the ramped thermal constraints. The fractional computations for the set of flow problems were performed with implementations of the Atangana-Baleanu (AB) and Caputo-Fabrizio (CF) analytical techniques. The integration process for such computations was achieved using the Laplace transformation. The comparative velocity and thermal analysis for the water and kerosene-oil-based nanofluid model is presented. The declining change in the velocity was observed due to the increase in the volume fraction of nanoparticles. It was observed that the increment in the temperature profile was more progressive for the kerosene oil and silver nanoparticle suspension.

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Applied Sciences

Liquid nanofilm is used in industrial applications, such as heat exchangers, water desalination s... more Liquid nanofilm is used in industrial applications, such as heat exchangers, water desalination systems, heat pumps, distillation systems, cooling systems, and complex engineering systems. The present work focuses on the numerical investigation of the condensation of falling liquid film containing different types of nanoparticles with a low-volume fraction. The nanofluid film falls inside a heat exchanger by mixed convection. The heat exchanger is composed of two parallel vertical plates. One of the plates is wetted and heated, while the other plate is isothermal and dry. The effect of the dispersion of the Cu or Al nanoparticles in the liquid on the heat exchange, mass exchange, and condensation process was analysed. The results showed that the heat transfer was enhanced by the dispersion of the nanoparticles in the water. The copper–water nanofluid presented the highest efficiency compared to the aluminium–water nanofluid and to the basic fluid (pure water) in terms of the heat an...

In this paper, a three-dimensional biomedical tissue phantom subjected to a short-pulse laser has... more In this paper, a three-dimensional biomedical tissue phantom subjected to a short-pulse laser has been studied. The FTn Finite Volume Method has been applied to solve the transient radiative transfer equation for isotropic and anisotropic tissue phantom. Both Curved-Line Advection Method (CLAM) and STEP schemes have been investigated. The transmittance and reflectance radiative signals have been analysed. The present predictions are confirmed by comparison with the solutions of the Monte Carlo method. The CLAM predictions proved that a decrease of the false scattering and ray effects are obtained and a good agreement with the reference solutions has been achieved. However, the STEP results are slight mismatching the solutions of the reference method. Then, the effects of the optical thickness, the albedo, and the asymmetry factor of the tissue phantom on the radiative signals have been examined. The results proved that a decrease of the peak transmittance is obtained when the optica...

Thermal Science, 2018

In this paper, 3-D heterogeneous medium, containing small inhomogeneous zones, subjected to a sho... more In this paper, 3-D heterogeneous medium, containing small inhomogeneous zones, subjected to a short-pulse laser has been examined by solving the transient radiative transfer equation. Both curved-line advection method and STEP schemes of the FTn finite volume method have been applied. The curved-line advection method predictions proved that a decrease of the false scattering and ray effects are obtained. In fact, there was a good agreement between the curved-line advection method and the Monte Carlo method. However, the STEP results are slightly mismatching the predictions of the aforementioned reference method. Then, the effects of the absorption coefficient, the size, the number and the position of inhomogeneous zone on the transmittance and reflectance signals have been analyzed. The predictions showed that the increase of the size of the inhomogeneity reduces the intensity of radiation. For both homogenous and heterogonous medium, the change of the detector position varies both ...

DESALINATION AND WATER TREATMENT, 2017

A computational study is reported on the combined heat and mass transfer during evaporation of bi... more A computational study is reported on the combined heat and mass transfer during evaporation of binary liquid film. The binary film is falling down on a vertical channel by mixed convection. The first plate is submitted to a constant heated flux while the other is isothermal and dry. The liquid mixture consists of ethylene glycol and water while the gas mixture is made up of three components: water vapour, ethylene glycol vapour and dry air. The results concern the influence of the operating parameters in the liquid and in the gas on the thickness of the binary liquid film and on the cumulated evaporation rate of binary liquid film.

International Journal of Thermal Sciences, 2017

Abstract The numerical study of coupled heat and mass transfer during the evaporation of flowing ... more Abstract The numerical study of coupled heat and mass transfer during the evaporation of flowing liquid film has been analysed. The film falls down on one plate of a vertical channel under free convection. The wetted plate is covered with a thin porous layer and externally subjected to a uniform heated flux while the second one is dry and isothermal. The liquid consists of pure water film while the gas mixture has two components: dry air and water vapour. The results concern the influence of porosity and porous layer thickness of the porous media on the coupled heat and mass transfer performance and on the film evaporation. The results show that, in the free convection, the presence of the porous layer enhances the heat and mass transfer performance at the liquid-gas interface during the liquid film evaporation.

Journal of Porous Media, 2016

International Journal of Engineering & Technology, 2016

This paper investigates the numerical analysis to determine the thermo-physical characteristics o... more This paper investigates the numerical analysis to determine the thermo-physical characteristics of materials. This method is based on a heating probe kept at a constant temperature and maintained in contact with a cylindrical sample. The heat power dissipated in the sample is measured by the probe. The results address to identify simultaneously the thermal conductivity, the volumetric heat capacity and the heat transfer coefficient using the inverse problem.

Journal of Thermal Science, 2010

This paper deals with a numerical analysis of the evaporation of a thin binary liquid film by for... more This paper deals with a numerical analysis of the evaporation of a thin binary liquid film by forced convection inside a channel constituted by two plates. The first plate is externally insulated and wetted by a thin water ethylene glycol film while the second is dry and isothermal. The first part is concerned with the effects of inlet ambiance conditions and the liquid concentration of ethylene glycol on the distribution of the velocity, temperature, concentrations profiles and the axial variation of the evaporation rate. The second part is focused on the inversion temperature point of the evaporation of binary liquid film. Results show that the inversion temperature phenomenon for the evaporation of binary liquid mixture is observed for high liquid concentration of ethylene glycol. The present results show that in the inlet temperature range considered here, the inversion temperature does not exit for the evaporation of pure ethylene glycol.

Thermal Science, 2017

This paper investigates a numerical analysis of coupled heat and mass transfer during the simulta... more This paper investigates a numerical analysis of coupled heat and mass transfer during the simultaneous evaporation and condensation in the presence of a binary liquid film flowing on one of two parallel vertical plates under mixed convection. The first plate of a vertical channel is externally insulated and wetted by a binary liquid film while the second one is dry and isothermal. The liquid mixture consists of water (the more volatile component) and ethylene glycol while the gas mixture has three components: dry air, water vapour and ethylene glycol vapour. The conducted simulations enable the analysis of the heat and mass transfer during water evaporation and ethylene glycol condensation for different inlet gas properties. It is found that an increase of the inlet vapour concentration of ethylene glycol enhances the water evaporation while the increase of the inlet vapour concentration of water slightly enhances the ethylene glycol vapour condensation. The increase of inlet gas te...

Current Applied Physics, Mar 1, 2016

We present a self-consistent calculation combined with the 16-band anticrossing model in order to... more We present a self-consistent calculation combined with the 16-band anticrossing model in order to investigate the electronic and optical properties of n-doped GaNAsBi/GaAs multiple-QWs operating at 1.55 µm. Optoelectronic features of these quantum structures seem advantageous for the design of photodetector devices. We have found that doping induces a blue shift of the fundamental transition energy for the uncoupled double-QWs with the barrier width L b = 12 nm. This transition energy shows a red shift when the doped DQWs are coupled (L b = 2 nm). An applied electric field favors further this shift. The coupling and Stark effects on the spatial distribution of confined electrons density are discussed. The absorption coefficient for the coupled 4 nm GaN .04 As .89 Bi .07 /GaAs DQWs is enhanced compared to the un-doped or uncoupled DQWs. Finally, we have examined the dependence of the absorption magnitude on the doping density and electric field for different values of wells number.

Journal of Alloys and Compounds, 2015

By applying the band anticrossing model combined with the envelope function formalism, a theoreti... more By applying the band anticrossing model combined with the envelope function formalism, a theoretical study of optoelectronic properties of lattice matched GaNAsBi-based multiple quantum wells (MQWs) operating at 1.55 μm was performed. Indeed, the electronic band structure of 4.5 nm GaN.04As.89Bi.07/GaAs double quantum wells (DQWs) was computed for a barrier width (Lb) varying from 1 to 12 nm. We found that the coupling between GaNAsBi wells which occurs for Lb ≤ 8 nm, modifies the confined energies levels and the fundamental interband transition of the coupled GaNAsBi/GaAs DQWs. This produces a slight shift of the wavelength emission from 1.55 μm. We have also discussed the coupling effect on the in-plane carrier effective mass and the optical absorption spectra of these DQWs. Basing on the enhancement of electron mobility and the slight amelioration of absorption peak magnitude brought by the well coupling, we have chosen the GaN.04As.89Bi.07/GaAs DQWs with Lb = 3.5 nm and Lw modified to 4.3 nm as a candidate for optoelectronic devices operating exactly at 1.55 μm. Finally, we are focused on the investigation of the optical properties of 7(GaAs)3.56(GaN.04As.89Bi.07)4.1 superlattices (SLs) operating at 1.55 μm especially the absorption coefficient behavior.

Semiconductors, 2015

Band structures of GaN 0.58y As 1-1.58y Bi y /GaAs quantum wells (QWs) were studied using the ban... more Band structures of GaN 0.58y As 1-1.58y Bi y /GaAs quantum wells (QWs) were studied using the band anticrossing model and the envelope function approximation. The confined states energies and the oscillator strengths of interband transitions were determined for well widths L W and Bi composition y varying in the range of 4-10 nm and 0-0.07 respectively. The emissions 1.3 and 1.55 µm were reached for specific couples (L W , y). The band anticrossing effect on the in plane carriers effective mass has been investigated at k = 0. The absorbance spectra were calculated for QWs operating at 1.3 and 1.55 µm.

Infrared Physics & Technology, 2014

h i g h l i g h t s GaAs 1Àx Bi x band structures have been calculated using Valence-BAC models. ... more h i g h l i g h t s GaAs 1Àx Bi x band structures have been calculated using Valence-BAC models. Reduction of E g by 81 meV/%Bi accompanied by an increase of D so+ by 56 meV/%Bi. A crossover at 0.73 eV has occurred between E g and D so+ for GaAs .88 Bi .12. Bismuth composition dependence on effective mass was discussed. Intrinsic carrier density increases with both Bi composition and temperature.

Materials Science in Semiconductor Processing, 2014

Band structures of n-i doped lattice-matched GaNAsBi/GaAs quantum wells are studied theoretically... more Band structures of n-i doped lattice-matched GaNAsBi/GaAs quantum wells are studied theoretically using a self-consistent calculation (based on the envelop function formalism) combined with the 16-band anti-crossing model. Operating at 1.55 μm, these QWs can represent active zones of temperature-insensitive optoelectronic device applications intended for optical fiber communications. We have calculated physical parameters of the structures such as the confining potential profiles, the Fermi level, the subband energies and their corresponding wavefunctions as well as the oscillator strength of interband transitions, the subband occupations, and the confined electrons density distributions. Finally, the absorption coefficient spectra of GaNAsBi-based QWs are also computed.

Infrared Physics & Technology, 2013

h i g h l i g h t s GaNAsBi band structures have been calculated using BAC model and k Á p method... more h i g h l i g h t s GaNAsBi band structures have been calculated using BAC model and k Á p method. Band-gap energy of GaNAsBi lattice matched to GaAs decreases by 198 meV/%Bi. Spin-orbit splitting increases by 56 meV/%Bi regardless N content. A crossover at about 0.6 eV has occurred between E g and D so of GaN .039 As .893 Bi .068. Effective masses behaviors of carriers have been discussed at C point.

Frontiers in Mechanical Engineering

The ammonia-water film condensation is used as an efficient working fluid in industrial applicati... more The ammonia-water film condensation is used as an efficient working fluid in industrial applications such as refrigeration, plate condenser and evaporator, absorber/generator heat exchange, air-conditioning, heat pumps and separation processes. The present work focuses on a numerical investigation of water-ammonia condensation on a falling binary liquid film inside a parallel plate condenser by mixed convection. The parallel plate condenser is composed by two parallel vertical plates. One of the plates is wetted by liquidfilm and cooled by the thermal flux cooling while the other plate is isothermal and dry. Parametric computations were performed to investigate the effects of the inlet parameters of gas, the properties of the binary liquid film as well as the thermal flux cooling on the combined mass and heat transfer and on the efficiency of the parallel plate condenser. The results show that an increase in the inlet vapor of ammonia as well as of vapor water enhances the efficienc...

The ammonia-water film condensation is used as an efficient working fluid in industrial applicati... more The ammonia-water film condensation is used as an efficient working fluid in industrial applications such as refrigeration, plate condenser and evaporator, absorber/generator heat exchange, airconditioning , heat pumps and separation processes. The present work focuses on a numerical investigation of water-ammonia condensation on a falling binary liquid film inside a parallel plate condenser by mixed convection. The parallel plate condenser is composed by two parallel vertical plates. One of the plates is wetted by liquidfilm and cooled by the thermal flux cooling while the other plate is isothermal and dry. Parametric computations were performed to investigate the effects of the inlet parameters of gas, the properties of the binary liquid film as well as the thermal flux cooling on the combined mass and heat transfer and on the efficiency of the parallel plate condenser. The results show that an increase in the inlet vapor of ammonia as well as of vapor water enhances the efficiency of the parallel plate condenser. It is shown also that an enhancement of efficiency of the parallel plate condenser has been recorded when the thermal flux cooling and inlet liquid flow rate is elevated. Whereas the increase of the inlet liquid concentration of ammonia inhibits the efficiency of the parallel plate condenser.

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

A fractional model was developed for presenting the thermal assessment of nanoparticles in an inc... more A fractional model was developed for presenting the thermal assessment of nanoparticles in an inclined moving surface. Water was used as a base fluid, while the nanofluid utilized copper oxide and silver nanoparticles. The modification of the thermal model was further supported by mixed convection, magnetic force, and porous saturated space. Slip effects to the porous surface were also introduced. The fluctuation in temperature at different times was assumed by following the ramped thermal constraints. The fractional computations for the set of flow problems were performed with implementations of the Atangana-Baleanu (AB) and Caputo-Fabrizio (CF) analytical techniques. The integration process for such computations was achieved using the Laplace transformation. The comparative velocity and thermal analysis for the water and kerosene-oil-based nanofluid model is presented. The declining change in the velocity was observed due to the increase in the volume fraction of nanoparticles. It was observed that the increment in the temperature profile was more progressive for the kerosene oil and silver nanoparticle suspension.

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Applied Sciences

Liquid nanofilm is used in industrial applications, such as heat exchangers, water desalination s... more Liquid nanofilm is used in industrial applications, such as heat exchangers, water desalination systems, heat pumps, distillation systems, cooling systems, and complex engineering systems. The present work focuses on the numerical investigation of the condensation of falling liquid film containing different types of nanoparticles with a low-volume fraction. The nanofluid film falls inside a heat exchanger by mixed convection. The heat exchanger is composed of two parallel vertical plates. One of the plates is wetted and heated, while the other plate is isothermal and dry. The effect of the dispersion of the Cu or Al nanoparticles in the liquid on the heat exchange, mass exchange, and condensation process was analysed. The results showed that the heat transfer was enhanced by the dispersion of the nanoparticles in the water. The copper–water nanofluid presented the highest efficiency compared to the aluminium–water nanofluid and to the basic fluid (pure water) in terms of the heat an...

In this paper, a three-dimensional biomedical tissue phantom subjected to a short-pulse laser has... more In this paper, a three-dimensional biomedical tissue phantom subjected to a short-pulse laser has been studied. The FTn Finite Volume Method has been applied to solve the transient radiative transfer equation for isotropic and anisotropic tissue phantom. Both Curved-Line Advection Method (CLAM) and STEP schemes have been investigated. The transmittance and reflectance radiative signals have been analysed. The present predictions are confirmed by comparison with the solutions of the Monte Carlo method. The CLAM predictions proved that a decrease of the false scattering and ray effects are obtained and a good agreement with the reference solutions has been achieved. However, the STEP results are slight mismatching the solutions of the reference method. Then, the effects of the optical thickness, the albedo, and the asymmetry factor of the tissue phantom on the radiative signals have been examined. The results proved that a decrease of the peak transmittance is obtained when the optica...

Thermal Science, 2018

In this paper, 3-D heterogeneous medium, containing small inhomogeneous zones, subjected to a sho... more In this paper, 3-D heterogeneous medium, containing small inhomogeneous zones, subjected to a short-pulse laser has been examined by solving the transient radiative transfer equation. Both curved-line advection method and STEP schemes of the FTn finite volume method have been applied. The curved-line advection method predictions proved that a decrease of the false scattering and ray effects are obtained. In fact, there was a good agreement between the curved-line advection method and the Monte Carlo method. However, the STEP results are slightly mismatching the predictions of the aforementioned reference method. Then, the effects of the absorption coefficient, the size, the number and the position of inhomogeneous zone on the transmittance and reflectance signals have been analyzed. The predictions showed that the increase of the size of the inhomogeneity reduces the intensity of radiation. For both homogenous and heterogonous medium, the change of the detector position varies both ...

DESALINATION AND WATER TREATMENT, 2017

A computational study is reported on the combined heat and mass transfer during evaporation of bi... more A computational study is reported on the combined heat and mass transfer during evaporation of binary liquid film. The binary film is falling down on a vertical channel by mixed convection. The first plate is submitted to a constant heated flux while the other is isothermal and dry. The liquid mixture consists of ethylene glycol and water while the gas mixture is made up of three components: water vapour, ethylene glycol vapour and dry air. The results concern the influence of the operating parameters in the liquid and in the gas on the thickness of the binary liquid film and on the cumulated evaporation rate of binary liquid film.

International Journal of Thermal Sciences, 2017

Abstract The numerical study of coupled heat and mass transfer during the evaporation of flowing ... more Abstract The numerical study of coupled heat and mass transfer during the evaporation of flowing liquid film has been analysed. The film falls down on one plate of a vertical channel under free convection. The wetted plate is covered with a thin porous layer and externally subjected to a uniform heated flux while the second one is dry and isothermal. The liquid consists of pure water film while the gas mixture has two components: dry air and water vapour. The results concern the influence of porosity and porous layer thickness of the porous media on the coupled heat and mass transfer performance and on the film evaporation. The results show that, in the free convection, the presence of the porous layer enhances the heat and mass transfer performance at the liquid-gas interface during the liquid film evaporation.

Journal of Porous Media, 2016

International Journal of Engineering & Technology, 2016

This paper investigates the numerical analysis to determine the thermo-physical characteristics o... more This paper investigates the numerical analysis to determine the thermo-physical characteristics of materials. This method is based on a heating probe kept at a constant temperature and maintained in contact with a cylindrical sample. The heat power dissipated in the sample is measured by the probe. The results address to identify simultaneously the thermal conductivity, the volumetric heat capacity and the heat transfer coefficient using the inverse problem.

Journal of Thermal Science, 2010

This paper deals with a numerical analysis of the evaporation of a thin binary liquid film by for... more This paper deals with a numerical analysis of the evaporation of a thin binary liquid film by forced convection inside a channel constituted by two plates. The first plate is externally insulated and wetted by a thin water ethylene glycol film while the second is dry and isothermal. The first part is concerned with the effects of inlet ambiance conditions and the liquid concentration of ethylene glycol on the distribution of the velocity, temperature, concentrations profiles and the axial variation of the evaporation rate. The second part is focused on the inversion temperature point of the evaporation of binary liquid film. Results show that the inversion temperature phenomenon for the evaporation of binary liquid mixture is observed for high liquid concentration of ethylene glycol. The present results show that in the inlet temperature range considered here, the inversion temperature does not exit for the evaporation of pure ethylene glycol.

Thermal Science, 2017

This paper investigates a numerical analysis of coupled heat and mass transfer during the simulta... more This paper investigates a numerical analysis of coupled heat and mass transfer during the simultaneous evaporation and condensation in the presence of a binary liquid film flowing on one of two parallel vertical plates under mixed convection. The first plate of a vertical channel is externally insulated and wetted by a binary liquid film while the second one is dry and isothermal. The liquid mixture consists of water (the more volatile component) and ethylene glycol while the gas mixture has three components: dry air, water vapour and ethylene glycol vapour. The conducted simulations enable the analysis of the heat and mass transfer during water evaporation and ethylene glycol condensation for different inlet gas properties. It is found that an increase of the inlet vapour concentration of ethylene glycol enhances the water evaporation while the increase of the inlet vapour concentration of water slightly enhances the ethylene glycol vapour condensation. The increase of inlet gas te...