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Titre : Contribution à l’étude des transferts thermiques dans les nanofluides. Type de document : texte imprimé Auteurs : Ahlam Ghennai, Auteur ; Rachid Bessaih, Directeur de thèse Mention d'édition : 07/06/2021 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2021 Importance : 136 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Génie MécaniqueTags : G.Mécanique: Energétique Transfert thermique simulation numérique cavité canal nanofluides génération d’entropie modèle de mélange
Heat transfer numerical simulation cavity channel nanofluids entropy generation mixture model الحمل الحراري المحاكاة العددية التجويف القناة الموائع النانوية توليد الإنتروبيا نموذج الخليطIndex. décimale : 620 Génie Mécanique Résumé :
This thesis deals with the numerical modelling of laminar natural and mixed convection flows of different anofluids types. Numerical simulations were performed using Ansysfluent software, considering three configurations: the square cavity, the cubic cavity, and the inclined channel. The numerical results obtained were validated with those found in the literature. A good agreement was obtained. We present three parts grouping the treated configurations: The first part concerns the study of 2-D natural convection in a square cavity equipped with a pentagonal obstacle, filled with a nanofluid (Cu/Water). The effects of the Rayleigh number Ra, the volumetric concentration of nanoparticles , the aspect ratio r and the orientation of the block were discussed The second part examines the 3-D mixed convection inside a cubic cavity with a heated square-section obstacle. This study compares the single carbon nanotube CNT/water nanofluid and the hybrid CNT-Copper/water nanofluid with different concentration ratios, Richardson number Ri, Reynolds number Re, and block aspect ratio r. In this case, three correlations have been developed to predict the average Nusselt number Nu's variation as a function of the chosen parameters. The third part deals with the numerical study of laminar mixed convection with entropy generation in an inclined channel with four heated blocks, traversed by a hybrid Al2O3- Cu/water nanofluid. In this part, the use of a two-phase mixing model approach was considered to demonstrate the effects of several parameters such as Ri, Re, , θ (the channel tilt), and the position of the block on Nusselt number, entropy generations, and Bejan number. Two different correlations were also determined to express Nu's average values for the position of aligned and non-aligned blocks.
Diplôme : Doctorat En ligne : ../theses/gmecanique/GHE7758.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11591 Contribution à l’étude des transferts thermiques dans les nanofluides. [texte imprimé] / Ahlam Ghennai, Auteur ; Rachid Bessaih, Directeur de thèse . - 07/06/2021 . - جامعة الإخوة منتوري قسنطينة, 2021 . - 136 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Génie MécaniqueTags : G.Mécanique: Energétique Transfert thermique simulation numérique cavité canal nanofluides génération d’entropie modèle de mélange
Heat transfer numerical simulation cavity channel nanofluids entropy generation mixture model الحمل الحراري المحاكاة العددية التجويف القناة الموائع النانوية توليد الإنتروبيا نموذج الخليطIndex. décimale : 620 Génie Mécanique Résumé :
This thesis deals with the numerical modelling of laminar natural and mixed convection flows of different anofluids types. Numerical simulations were performed using Ansysfluent software, considering three configurations: the square cavity, the cubic cavity, and the inclined channel. The numerical results obtained were validated with those found in the literature. A good agreement was obtained. We present three parts grouping the treated configurations: The first part concerns the study of 2-D natural convection in a square cavity equipped with a pentagonal obstacle, filled with a nanofluid (Cu/Water). The effects of the Rayleigh number Ra, the volumetric concentration of nanoparticles , the aspect ratio r and the orientation of the block were discussed The second part examines the 3-D mixed convection inside a cubic cavity with a heated square-section obstacle. This study compares the single carbon nanotube CNT/water nanofluid and the hybrid CNT-Copper/water nanofluid with different concentration ratios, Richardson number Ri, Reynolds number Re, and block aspect ratio r. In this case, three correlations have been developed to predict the average Nusselt number Nu's variation as a function of the chosen parameters. The third part deals with the numerical study of laminar mixed convection with entropy generation in an inclined channel with four heated blocks, traversed by a hybrid Al2O3- Cu/water nanofluid. In this part, the use of a two-phase mixing model approach was considered to demonstrate the effects of several parameters such as Ri, Re, , θ (the channel tilt), and the position of the block on Nusselt number, entropy generations, and Bejan number. Two different correlations were also determined to express Nu's average values for the position of aligned and non-aligned blocks.
Diplôme : Doctorat En ligne : ../theses/gmecanique/GHE7758.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11591 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité GHE/7758 GHE/7758 Thèse Bibliothèque principale Thèses Disponible
Titre : Étude des composants à base de cristaux photoniques : Application dans le domaine du démultiplexage et de la détection. Type de document : texte imprimé Auteurs : Safia Arafa, Auteur ; Mohamed Bouchemat, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 150 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueTags : cristaux photoniques l'optique intégrée biocapteurs démultiplexeur cavité FDTD Photonic crystal integrated optics biosensors demultiplexer cavity لبلورات الضوئية البصريات المتكاملة أجهزة الاستشعار البيولوجية مزيلات الدمج التجويف Index. décimale : 621 Electronique Résumé : Nowadays, the development of biological sensors has become a major issue in order to meet the current and the
future needs in diverse areas demanded. Real-time detection or analysis should be preferred and the response should be easy to read and extremely fast. In parallel, the progress of nanotechnologies and in particular those of photonic crystals, which make it possible to manipulate the light at nanometric resolution, and thus at the biomolecule scale, offers the possibility of achieving a new high-performed detection platform.
In this context, this thesis aims to study and to design refractive index biosensors based on photonic crystals. The structures proposed are essentially based on a H0 cavity coupled waveguide system. The main objective of our work remains the enhancement of light confinement within the cavity area. In the first part of this work we analyze in detail the influence of the cavity geometry on the detection performances. Thus, we present a configuration based on ringed air holes to improve the detection properties. In order to integrate several detection units in the same photonic crystal platform, the wavelength division demultiplexing (WDM) technique to spatially separate the responses of the integrated biosensors will be studied: Two structures of demultiplexers based on a selective filtering will also be presented. As for the case of a single biosensor and based on this technique the configurations of classical and ringed biosensor array will be studied and simultaneously evaluated. The optical properties of these photonic structures will be numerically evaluated by performing simulations based on the finite difference time domain (FDTD) method. The obtained results indicate that the response of each sensor unit shifts independently in terms of refractive index variations. Accordingly, a sensitivity of 450 nm / RIU and a crosstalk of less than -43.78 dB have been achieved for the ringed configuration, while maintaining a quality factor as high as 5.74×104. These features make the designed structure a promising platform for performing monolithic integration and high multiplexed label-free detection.Diplôme : Doctorat En ligne : ../theses/electronique/ARA7278.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10893 Étude des composants à base de cristaux photoniques : Application dans le domaine du démultiplexage et de la détection. [texte imprimé] / Safia Arafa, Auteur ; Mohamed Bouchemat, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 150 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueTags : cristaux photoniques l'optique intégrée biocapteurs démultiplexeur cavité FDTD Photonic crystal integrated optics biosensors demultiplexer cavity لبلورات الضوئية البصريات المتكاملة أجهزة الاستشعار البيولوجية مزيلات الدمج التجويف Index. décimale : 621 Electronique Résumé : Nowadays, the development of biological sensors has become a major issue in order to meet the current and the
future needs in diverse areas demanded. Real-time detection or analysis should be preferred and the response should be easy to read and extremely fast. In parallel, the progress of nanotechnologies and in particular those of photonic crystals, which make it possible to manipulate the light at nanometric resolution, and thus at the biomolecule scale, offers the possibility of achieving a new high-performed detection platform.
In this context, this thesis aims to study and to design refractive index biosensors based on photonic crystals. The structures proposed are essentially based on a H0 cavity coupled waveguide system. The main objective of our work remains the enhancement of light confinement within the cavity area. In the first part of this work we analyze in detail the influence of the cavity geometry on the detection performances. Thus, we present a configuration based on ringed air holes to improve the detection properties. In order to integrate several detection units in the same photonic crystal platform, the wavelength division demultiplexing (WDM) technique to spatially separate the responses of the integrated biosensors will be studied: Two structures of demultiplexers based on a selective filtering will also be presented. As for the case of a single biosensor and based on this technique the configurations of classical and ringed biosensor array will be studied and simultaneously evaluated. The optical properties of these photonic structures will be numerically evaluated by performing simulations based on the finite difference time domain (FDTD) method. The obtained results indicate that the response of each sensor unit shifts independently in terms of refractive index variations. Accordingly, a sensitivity of 450 nm / RIU and a crosstalk of less than -43.78 dB have been achieved for the ringed configuration, while maintaining a quality factor as high as 5.74×104. These features make the designed structure a promising platform for performing monolithic integration and high multiplexed label-free detection.Diplôme : Doctorat En ligne : ../theses/electronique/ARA7278.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10893 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité ARA/7278 ARA/7278 Thèse Bibliothèque principale Thèses Disponible
Titre : Étude de cristaux photoniques en silicium pour l'application à la biodétection Type de document : texte imprimé Auteurs : Dallel Benelarbi, Auteur ; Touraya Bouchemat, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 120 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ElectroniqueTags : cristaux photoniques silicium biocapteurs guide d'onde cavité SOI sensibilité FDTD-2D photonic crystals silicon biosensors waveguide cavity sensitivity البلورات الضوئية سيليسيوم المستشعرات الضوئية الدليل الموجي التجويف .FDTD-2D الحساسبةSOI Index. décimale : 621 Electronique Résumé : This thesis is dedicated to the study and design of new structures for optical detection. Indeed, the development of these optical devices has a growing and particular interest, particularly for targeting and identifying biological species. For this purpose, the photonic crystal-based components (CPs) have been widely exploited in the field of bio-detection.
Silicon is an ideal candidate designated as a support material for the realization of these devices. In this context, new coupling techniques between waveguide and optical cavity based on planar photonic crystals, made on a silicon-on-insulator (SOI) substrate, have been developed. To do this, we are modeling these bio detectors, optimizing their key parameters such as the quality factor and sensitivity to the optical index of the external environment, using commercial software Fullwave and Crystalwave that exploit the finite difference method in the two-dimensional time domain (FDTD-2D). We first studied the parallel coupling between a resonant cavity and a waveguide (W1) for application to the detection of DNA biomolecules. The originality of this study is to consider several sensors on a single platform, and to demonstrate that each sensor could detect a target independently and without interaction with others, without losses, and this, by acting on the parameters influencing the
essential characteristics, we note a high sensitivity and a low limit of detection. As for the second geometry studied, it consists of another coupling path, the latter comprises two sections of guides W1 between which has been arranged a ring cavity. We have also optimized the different structural parameters for this configuration, in order to improve the sensitivity and the quality factor in order to obtain another type of high-performance sensor, namely the temperature sensor. For this, we consider the evolution of the sensitivity as a function of the change in the temperature of the water, convincing results were noted.
Diplôme : Doctorat En ligne : ../theses/electronique/BEN7253.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10845 Étude de cristaux photoniques en silicium pour l'application à la biodétection [texte imprimé] / Dallel Benelarbi, Auteur ; Touraya Bouchemat, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 120 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ElectroniqueTags : cristaux photoniques silicium biocapteurs guide d'onde cavité SOI sensibilité FDTD-2D photonic crystals silicon biosensors waveguide cavity sensitivity البلورات الضوئية سيليسيوم المستشعرات الضوئية الدليل الموجي التجويف .FDTD-2D الحساسبةSOI Index. décimale : 621 Electronique Résumé : This thesis is dedicated to the study and design of new structures for optical detection. Indeed, the development of these optical devices has a growing and particular interest, particularly for targeting and identifying biological species. For this purpose, the photonic crystal-based components (CPs) have been widely exploited in the field of bio-detection.
Silicon is an ideal candidate designated as a support material for the realization of these devices. In this context, new coupling techniques between waveguide and optical cavity based on planar photonic crystals, made on a silicon-on-insulator (SOI) substrate, have been developed. To do this, we are modeling these bio detectors, optimizing their key parameters such as the quality factor and sensitivity to the optical index of the external environment, using commercial software Fullwave and Crystalwave that exploit the finite difference method in the two-dimensional time domain (FDTD-2D). We first studied the parallel coupling between a resonant cavity and a waveguide (W1) for application to the detection of DNA biomolecules. The originality of this study is to consider several sensors on a single platform, and to demonstrate that each sensor could detect a target independently and without interaction with others, without losses, and this, by acting on the parameters influencing the
essential characteristics, we note a high sensitivity and a low limit of detection. As for the second geometry studied, it consists of another coupling path, the latter comprises two sections of guides W1 between which has been arranged a ring cavity. We have also optimized the different structural parameters for this configuration, in order to improve the sensitivity and the quality factor in order to obtain another type of high-performance sensor, namely the temperature sensor. For this, we consider the evolution of the sensitivity as a function of the change in the temperature of the water, convincing results were noted.
Diplôme : Doctorat En ligne : ../theses/electronique/BEN7253.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10845 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/7253 BEN/7253 Thèse Bibliothèque principale Thèses Disponible
