Comparison of numerical solvers for two-fluid turbulence processing
Description
The aim of this thesis is to simulate a compressive turbulent multicomponent flow by different numerical methods. First of all, from a bibliographical analysis of turbulent models based on the statistical theory of splitting, a multicomponent model for turbulent flow is derived. The flow is supposed to be isentropic, like in the P-system. The evolution equation of the kinetic turbulent energy is established for the mixture. A generalization of the one-component turbulent equation is obtained. Following section is devoted to the exact resolution of the convective part of the system. The hyperbolicity is demonstrated and then, by an entropy criterion the unique solution is exhibited. If the initial states are not too far, the vacuum does not appear and the associated Riemann Problem admits a unique solution. In the last part, a generalization of this study to the multidimensional framework is done. Different tests of 2D multicomponent turbulent flows are introduced, and the results by a 1D comparison between the costly exact solver of the Godunov scheme and two linearized schemes are improved. Rusanov scheme and Vfroe-nc do not have the precision required in specific tests. The costly accuracy of Godunov scheme is justified. This work is continued with the diffusive part computation of the complete K-Epsilon model. (author)
Abstract (French)
Le but de cette these est de simuler, par plusieurs methodes numeriques, un ecoulement compressible bifluide, turbulent. Dans une premiere partie du travail correspondant a une analyse bibliographique, nous etudions diverses modelisations d'ecoulements turbulents, avec une approche privilegiee pour la theorie statistique du splitting et les modeles multi-fluides. Nous batissons l'equation d'evolution de l'energie cinetique turbulente du melange, generalisant celle d'un ecoulement mono-fluide. Ceci permet l'elaboration d'un modele bifluide turbulent. La seconde partie du travail consiste a donner une resolution exacte de la partie convective du systeme dont on prouve l'hyperbolicite. Nous nous interessons particulierement aux criteres entropiques permettant de caracteriser l'unique solution. Cette analyse debouche sur la resolution du systeme pour des conditions initiales correspondant a un probleme de Riemann. Dans la troisieme partie, nous presentons les resultats numeriques de l'implementation du schema de Godunov. Plusieurs cas 2D de turbulence bifluide sont donnes, ainsi qu'une validation numerique par comparaison de la solution 1D a la solution exacte du solveur de Riemann. Pour reduire le temps de calcul, nous proposons deux solveurs approches: le schema Vfroe-nc et le schema de Rusanov. Ceux-ci montrent cependant leurs faiblesses quant a la fiabilite du resultat. Ainsi, nous avons privilegie une resolution par solveur exact du modele bifiuide turbulent puisque la robustesse du schema le necessitait. Ce travail se poursuit par la prise en compte de la partie diffusive du modele K-Epsilon complet. (auteur)Files
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Additional details
Additional titles
- Original title (French)
- Comparaison de solveurs numeriques pour le traitement de la turbulence bifluide
Publishing Information
- Imprint Pagination
- 226 p.
- Report number
- FRNC-TH--12326
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 53004321
- Subject category
- S42: ENGINEERING; S97: MATHEMATICAL METHODS AND COMPUTING;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- ALGORITHMS; BUBBLES; COMPRESSIBLE FLOW; CONVECTION; EIGENVECTORS; ENTROPY; FINITE ELEMENT METHOD; INTERFACES; KINETIC ENERGY; MOMENTUM TRANSFER; NOZZLES; RANKINE-HUGONIOT EQUATIONS; SHOCK TUBES; SHOCK WAVES; TURBULENT FLOW; TWO-PHASE FLOW; VALIDATION; WAVE PROPAGATION
- Descriptors DEC
- CALCULATION METHODS; ENERGY; ENERGY TRANSFER; EQUATIONS; FLUID FLOW; HEAT TRANSFER; MASS TRANSFER; MATHEMATICAL LOGIC; MATHEMATICAL SOLUTIONS; NUMERICAL SOLUTION; PHYSICAL PROPERTIES; TESTING; THERMODYNAMIC PROPERTIES
Optional Information
- Notes
- 53 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses