Please use this identifier to cite or link to this item:
http://dspace.univ-tiaret.dz:80/handle/123456789/11654| Title: | SIMULATION NUMERIQUE D’UN JET TURBULENT AXISYMETRIQUE |
| Authors: | KHALFA, LAZREG |
| Keywords: | écoulements turbulents simulation numérique |
| Issue Date: | 2017 |
| Publisher: | université Ibn Khaldoun |
| Abstract: | L'évolution des méthodes de calcul des écoulements turbulents oscille entre deux tendances. L'une d'elle est une recherche de techniques permettant de traiter une diversité de configurations aussi étendue que possible. Dans-cette optique on envisage un traitement unifier de l'ensemble des écoulements depuis l'écoulements " simple " de laboratoire où l'on étudier la décroissance de la turbulence derrière une grille jusqu'aux écoulements atmosphériques les plus complexes . L'autre voie est la recherche de modèles parfaitement adoptés aux différents types de problèmes rencontrés par exemple sur un avion,on distingue nettement les couches limites les sillages, les jets où notre application a été effectuée pour la simulation numérique de la diffusion Lagrangienne dans le jet axisymétrique, les couches de mélanges, les écoulements tourbillonnaires, etc.. |
| Description: | The evolution of methods for calculating turbulent flows oscillates between two trends. One of them is a search for techniques allowing to treat as wide a diversity of configurations as possible. In this perspective, a unified treatment of all the flows is envisaged from the "simple" laboratory flows where the decay of the turbulence behind a grid is studied to the most complex atmospheric flows. The other way is to find perfectly adopted models for the various types of problems encountered, for example, on an airplane, clearly distinguishing the boundary layers from the wakes, the jets where our application was performed for the numerical simulation of the Lagrangian diffusion in the Jet axisymmetric, mixing layers, vortex flows, etc ... Pres one by one, each of these types of flow can be calculated. In a very precise manner, but the difficulty is first of all to know how to identify these different units and then to connect them properly. This approach requires a very thorough knowledge of the physical problems to be dealt with and the possibilities of the models. In any case, turbulence remains a discipline where the use of experience is indispensable. To illustrate this point, for the experimental studies that have been done on the axisymmetric self-preservative jet the figures (VII-1, 2,3,4,5,6) show the state of the art in the 60 and 70 .The reduction of the dispersion of numerical results is mainly related to the publication of experimental results around which all the "prevision" have finally come together. In our work, the elaborated program allowed us to simulate the Lagrangian diffusion of an axisymmetric jet. These results seem very satisfactory to us because it approaches the reality. What can be said at last; It is that the paths of research in the field of turbulence are very diversified and we are far from possessing the key giving access to the solution of all turbulent flows and anyway, depending on the results sought and the purpose of the calculations performed, It seems necessary to have a range of methods ranging from the simplest practical techniques to the most complex theories that seek to elucidate the problem of turbulence |
| URI: | http://dspace.univ-tiaret.dz:80/handle/123456789/11654 |
| Appears in Collections: | Master |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| memoire.2.pdf | 929,02 kB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.