Faculté des Sciences appliquées
Faculté des Sciences appliquées

Master thesis and internship[BR]- Master's Thesis : Optimal criterion to define convergence in unsteady CFD simulations for applications in Formula 1 car aerodynamics[BR]- Internship (linked to master's thesis)

Cotteleer, Léo ULiège
Promotor(s) : Terrapon, Vincent ULiège
Date of defense : 25-Jun-2020/26-Jun-2020 • Permalink :
Title : Master thesis and internship[BR]- Master's Thesis : Optimal criterion to define convergence in unsteady CFD simulations for applications in Formula 1 car aerodynamics[BR]- Internship (linked to master's thesis)
Translated title : [fr] Critère optimal de convergence pour les simulations numériques d'écoulements instationnaires appliqué à l'aérodynamique d'une Formule 1
Author : Cotteleer, Léo ULiège
Date of defense  : 25-Jun-2020/26-Jun-2020
Advisor(s) : Terrapon, Vincent ULiège
Committee's member(s) : Andrianne, Thomas ULiège
Hahn, Marco 
Serino, Gennaro 
Language : English
Number of pages : 115
Keywords : [fr] CFD, aerodynamics, convergence, statistics
Discipline(s) : Engineering, computing & technology > Aerospace & aeronautics engineering
Target public : Researchers
Professionals of domain
General public
Institution(s) : Université de Liège, Liège, Belgique
Degree: Master en ingénieur civil en aérospatiale, à finalité spécialisée en "aerospace engineering"
Faculty: Master thesis of the Faculté des Sciences appliquées


[fr] Computational Fluid Dynamics (CFD) analyses have become a tool of choice to deepen phys- ical understanding and a precious help to solve practical problems. In the light of the continuous enhancement in computer power, the use of this new numerical tool is not planned to stop. This growth in computing capacity is leading to an increasing interest in scale-resolving turbulence such as detached-eddy simulation (DES). The unsteady pattern of the flow in Formula 1 racing therefore results to simulations that are very computational resources consuming. The resolution of numer- ous turbulent scales requires small time steps. In addition, time-dependent simulations take time to develop from arbitrary initial conditions to a statistically stationary state such that long samples are necessary for reliable statistical estimates. The initial transient duration and the required simulation time are highly case-specific, user burden and a priori unknown.
This work introduces a methodology that automates the initial transient estimation during a numerical CFD simulation and the prediction of the required simulation time to obtain reliable statistics. The techniques rely on statistical considerations for aerodynamic quantities of inter- est and have shown satisfactory results, in line with the a posteriori intuitions. In the two first parts, a rigorous mathematical background is provided and the methodology is described as well as its previous versions. In particular, a chapter is dedicated to the estimation of the statistical error by means of a second order model. The discussions and results provide a wide range of im- plementation issues and test cases. Especially, Delayed Detached Eddy Simulations (DDES) are performed for common bluff bodies (high angle-of-attack airfoil, triangular cylinder, rotating cir- cular cylinder). Finally, the methodology has been implemented as a User-Defined Function (UDF) in ANSYS Fluent and in the last chapter are exposed the different interesting quantifications that can be extrapolated from the methodology. A concise summary of the main outcomes is provided in the conclusion. The latter is written in such a way that each principle finding is linked to the corresponding section.



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  • Cotteleer, Léo ULiège Université de Liège > Master ingé. civ. aérospat., à fin.


Committee's member(s)

  • Andrianne, Thomas ULiège Université de Liège - ULiège > Département d'aérospatiale et mécanique > Interactions Fluide-Structure - Aérodynamique expérimentale
    ORBi View his publications on ORBi
  • Hahn, Marco Red Bull Technology
  • Serino, Gennaro Red Bull Technology
  • Total number of views 198
  • Total number of downloads 493

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