Feedback

Faculté des Sciences appliquées
Faculté des Sciences appliquées
MASTER THESIS
VIEW 98 | DOWNLOAD 1929

Fluid-structure interaction simulations of separated flows through Detached Eddy Simulations

Download
Gómez Gómez, Rubén ULiège
Promotor(s) : Terrapon, Vincent ULiège
Date of defense : 7-Sep-2017/8-Sep-2017 • Permalink : http://hdl.handle.net/2268.2/3118
Details
Title : Fluid-structure interaction simulations of separated flows through Detached Eddy Simulations
Author : Gómez Gómez, Rubén ULiège
Date of defense  : 7-Sep-2017/8-Sep-2017
Advisor(s) : Terrapon, Vincent ULiège
Committee's member(s) : Dimitriadis, Grigorios ULiège
Güner, Hüseyin ULiège
Language : English
Number of pages : 93
Keywords : [en] CFD
[en] Unsteady RANS
[en] Detached-Eddy Simulations
[en] Turbulent separated flows
[en] OpenFOAM
[en] SU2
[en] DMD
Discipline(s) : Engineering, computing & technology > Aerospace & aeronautics engineering
Institution(s) : Université de Liège, Liège, Belgique
Universidad Politécnica de Madrid, Madrid, Spain
Degree: Cours supplémentaires destinés aux étudiants d'échange (Erasmus, ...)
Faculty: Master thesis of the Faculté des Sciences appliquées

Abstract

[en] The research in the field of Computational Fluid Dynamic in turbulent separated flows is a hot topic in the industrial and academic aerospace sector. Aeronautic industrial standards require each time better and more powerful CFD methods to inquire the behavior of turbulent flows as a consequence of their growing use in aeronautical design. They are extremely important in almost every engineering discipline, especially in those which are facing aerodynamic and structural design; as aerospace, vehicle or naval engineering.

This present master thesis centers its work exploring the turbulent separated flow physics and vortex detachment in a simple flat plate geometry. In the first place, the flat plate profile was considered static at an angle of attack of 30 degrees and 4e4 Re. In the second case, the flat plate was moved with a large oscillation angle of attack at a determined frequency of rotation in pitching motion. The simulation results were compared with experiments, trying to reproduce the reality of the flow behavior and detecting possible discrepancies.

For every case, a mesh refinement study was performed, reducing the numerical error to stabilize the solution. The aerodynamic coefficients, shedding frequency and vortex detachment results were presented for unsteady RANS and DDES approaches with two solvers: OpenFOAM and SU2, both open-source software. Moreover, a certain sensitivity analysis was accomplished to discern how the span-length or the pivot point parameter might affect the results. The analysis was completed shifting the turbulence modeling; Spalart-Allmaras and k-omega SST model of Menter were both verified.

The results in the static plate show a better approach with DDES method than with RANS, finding those pretty acceptable for both solvers. The high angle induces separation, increasing the relative error in the aerodynamic coefficients. The DDES case was able to predict the reality with an error around 8%. The shedding frequency was exactly the same that the one detected in the experiment, both in 3D URANS and DDES. On the other hand, the performances with OpenFOAM for the pitching plate have distortions when the plate is moved in rigid motion, although in SU2 those results were quite accurate, with errors bellow 5%. The k-omega SST model has positive consequences in the static plate, reducing the relative errors for both codes. However, in the pitching mode, the S-A model presents a better approach for both solvers, even if the outcomes in OF are quite poor.
Finally, and with the aim of further understanding the physics of the phenomena, the data resulting from the DDES cases were decomposed by using a Dynamic Mode Decomposition algorithm to extract the mode shapes.


File(s)

Document(s)

File
Access Abstract_RubenGomez.pdf
Description: -
Size: 99.24 kB
Format: Adobe PDF
File
Access TFE_RubenGomez.pdf
Description: -
Size: 17.81 MB
Format: Adobe PDF

Author

  • Gómez Gómez, Rubén ULiège Université de Liège > conv. Erasmus en sc. appl.

Promotor(s)

Committee's member(s)

  • Dimitriadis, Grigorios ULiège Université de Liège - ULg > Département d'aérospatiale et mécanique > Interactions Fluide-Structure - Aérodynamique expérimentale
    ORBi View his publications on ORBi
  • Güner, Hüseyin ULiège Université de Liège - ULg > Département d'aérospatiale et mécanique > Interactions Fluide-Structure - Aérodynamique expérimentale
    ORBi View his publications on ORBi
  • Total number of views 98
  • Total number of downloads 1929










All documents available on MatheO are protected by copyright and subject to the usual rules for fair use.
The University of Liège does not guarantee the scientific quality of these students' works or the accuracy of all the information they contain.