Monsieur : MITICHE Ilyes
Soutiendra sa thèse de Doctorat 3éme Cycle en Physique
Intitulé: «Etude des propriétés thérmophysiques de nanofluides utilisés pour la distillation solaire.»
Le : 08 Novembre 2021 à la salle de visioconférences du Centre des Systèmes et Réseaux de l’UMMTO, à 10 H:00
Directeur de Thèse : Professeur LAMROUS Omar
Devant le jury d’examen suivant :
Nom et Prénom | Grade | Lieu d’Exercice | Qualité |
M. BOUZAR Hamid | Professeur | UMMTO | Président |
M. LAMROUS Omar | Professeur | UMMTO | Directeur de Thèse |
Mme LAIDANI Nadhira | Chercher Senior | FBK(Italie) | Co-directeur |
M. BELABBAS Imed | Professeur | U.Béjaia | Examinateur |
M. DJOUDER Madjid | MCA | UMMTO | Examinateur |
M. ZENIA Hand | MCA | UMMTO | Examinateur |
M. MAKHLOUF Said | Professeur | UMMTO | Invité |
Mots clés
Distillateurs solaires, nanofluides, nanoparticules, conductivité thermique, dynamique moléculaire, théorie de la réponse linéaire, Green-Kubo, mouillabilité, nano-couche à l’interface, dépôt par plasma RF, potentiel zêta, stabilité.
Abstract
This doctoral thesis is devoted to the study of the thermal transport of copper nanofluids in order to quantify the importance of the main parameters, such as the concentration, the wettability and the size of the particles involved in improving thermal conductivity. In the first part, an efficient microscopic theoretical approach, the theory of the linear response assisted by simulations of molecular dynamics at equilibrium, made it possible to highlight the role of the nanolayer interface in the improvement of the thermal conductivity of nanofluids studied. The results of this research highlight the influence of the vibration modes of liquid argon atoms located around copper nanoparticles on thermal conductivity. Conclusions were drawn on the correlation between increased mean free path of vibrational modes of copper nanoparticles and increased thermal conductivity.
In a second experimental part, the elaboration of copper nanoparticles based on the RF plasma deposition method on a liquid substrate was carried out. First, after the description of the characteristic parameters of the deposit and the characterizations by spectrophotometry, atomic force microscopy and dynamic light scattering, the formation of Cu2O nanoparticles with a diameter ranging from a few to a hundred of nanometers was shown. Then, secondly, the influence of a number of experimental parameters on the nature, morphology and size of nanoparticles was reported. Moderate stability of the nanofluid was achieved. From an application point of view, all of these studies could lead to the optimization of the productivity of solar stills.
Keywords
Solar stills, nanofluids, nanoparticles, thermal conductivity, molecular dynamics, linear response theory, Green-Kubo, wettability, nano-layer interface, RF plasma deposition, zeta potential, stability.