Flow separation modelling through discrete vortex methods

The objective of the present Master thesis is to develop a flow separation model for airfoils (2D problems) in order to overcome the limitations of classical potential models where flow separation is not allowed. This is done through a meshless methodology called full cloud vortex method. This metho...

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Bibliographic Details
Author: Perez Gordo, José
Format: master thesis
Publication Date:2012
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2099.1/19192
Online Access:https://hdl.handle.net/2099.1/19192
Access Level:Open access
Keyword:Fluid dynamics --Mathematical models
Vortex-motion --Mathematical models
Flow separation
Discrete vortex methods
Aeroelastic effects
Dinàmica de fluids
Àrees temàtiques de la UPC::Aeronàutica i espai
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spelling Flow separation modelling through discrete vortex methodsPerez Gordo, JoséFluid dynamics --Mathematical modelsVortex-motion --Mathematical modelsFlow separationDiscrete vortex methodsAeroelastic effectsDinàmica de fluidsÀrees temàtiques de la UPC::Aeronàutica i espaiThe objective of the present Master thesis is to develop a flow separation model for airfoils (2D problems) in order to overcome the limitations of classical potential models where flow separation is not allowed. This is done through a meshless methodology called full cloud vortex method. This method computes the solution in several steps. First one, the airfoil is discretized in panels and through classical potential methods, the vorticity over each panel is obtained. After that, the vorticity is concentrated in a single point and shed at a certain distance of the panel. Next step consists on the convection of this vorticity points under the influence of the flow field, the panels and the other vortices. In order to increase the accuracy, the final position is obtained from the computed velocity through a forward 2nd order integration method. In order to cope also viscous effects, a simple method to compute the diffusion of the vorticity of each shed vortex is also implemented. Finally, the pressure coefficient of each panel and the forces acting on the whole airfoil are computed. Once the forces are obtained, a dynamic analysis is carried on. In order to do that, a simple 2 degrees of freedom spring-mass-damper model is implemented. From it, the position, velocity and acceleration of every node of the discretized airfoil is computed. The velocities and accelerations are obtained through a 2nd order finite differences scheme. All the equations are implemented in Fortran, and the final program is introduced in a pre-post processor called GiD, which allows to generate the geometry, discretize it and set all the needed parameters up for for running the simulations. Finally, in order to test the code, three geometries are tested: A cylinder, a symmetric airfoil (NACA0012) and a non symmetric airfoil (NACA4412). The results obtained are compared with experimental results in order to check the correct behaviour of the code. In all the 3 simulated geometries, the results are in good agreement with the experimental ones.Universitat Politècnica de CatalunyaVillardi de Montlaur, Adeline dePons i Prats, Jordi20122012-11-0720132013-10-08master thesishttp://purl.org/coar/resource_type/c_bdccNAhttp://purl.org/coar/version/c_be7fb7dd8ff6fe43info:eu-repo/semantics/masterThesisapplication/pdfhttps://hdl.handle.net/2099.1/19192reponame:UPCommons. Portal del coneixement obert de la UPCinstname:Universitat Politècnica de Catalunya (UPC)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2Attribution-NonCommercial-ShareAlike 3.0 Spainhttp://creativecommons.org/licenses/by-nc-sa/3.0/es/info:eu-repo/semantics/openAccessoai:upcommons.upc.edu:2099.1/191922026-05-27T15:37:01Z
dc.title.none.fl_str_mv Flow separation modelling through discrete vortex methods
title Flow separation modelling through discrete vortex methods
spellingShingle Flow separation modelling through discrete vortex methods
Perez Gordo, José
Fluid dynamics --Mathematical models
Vortex-motion --Mathematical models
Flow separation
Discrete vortex methods
Aeroelastic effects
Dinàmica de fluids
Àrees temàtiques de la UPC::Aeronàutica i espai
title_short Flow separation modelling through discrete vortex methods
title_full Flow separation modelling through discrete vortex methods
title_fullStr Flow separation modelling through discrete vortex methods
title_full_unstemmed Flow separation modelling through discrete vortex methods
title_sort Flow separation modelling through discrete vortex methods
dc.creator.none.fl_str_mv Perez Gordo, José
author Perez Gordo, José
author_facet Perez Gordo, José
author_role author
dc.contributor.none.fl_str_mv Villardi de Montlaur, Adeline de
Pons i Prats, Jordi
dc.subject.none.fl_str_mv Fluid dynamics --Mathematical models
Vortex-motion --Mathematical models
Flow separation
Discrete vortex methods
Aeroelastic effects
Dinàmica de fluids
Àrees temàtiques de la UPC::Aeronàutica i espai
topic Fluid dynamics --Mathematical models
Vortex-motion --Mathematical models
Flow separation
Discrete vortex methods
Aeroelastic effects
Dinàmica de fluids
Àrees temàtiques de la UPC::Aeronàutica i espai
description The objective of the present Master thesis is to develop a flow separation model for airfoils (2D problems) in order to overcome the limitations of classical potential models where flow separation is not allowed. This is done through a meshless methodology called full cloud vortex method. This method computes the solution in several steps. First one, the airfoil is discretized in panels and through classical potential methods, the vorticity over each panel is obtained. After that, the vorticity is concentrated in a single point and shed at a certain distance of the panel. Next step consists on the convection of this vorticity points under the influence of the flow field, the panels and the other vortices. In order to increase the accuracy, the final position is obtained from the computed velocity through a forward 2nd order integration method. In order to cope also viscous effects, a simple method to compute the diffusion of the vorticity of each shed vortex is also implemented. Finally, the pressure coefficient of each panel and the forces acting on the whole airfoil are computed. Once the forces are obtained, a dynamic analysis is carried on. In order to do that, a simple 2 degrees of freedom spring-mass-damper model is implemented. From it, the position, velocity and acceleration of every node of the discretized airfoil is computed. The velocities and accelerations are obtained through a 2nd order finite differences scheme. All the equations are implemented in Fortran, and the final program is introduced in a pre-post processor called GiD, which allows to generate the geometry, discretize it and set all the needed parameters up for for running the simulations. Finally, in order to test the code, three geometries are tested: A cylinder, a symmetric airfoil (NACA0012) and a non symmetric airfoil (NACA4412). The results obtained are compared with experimental results in order to check the correct behaviour of the code. In all the 3 simulated geometries, the results are in good agreement with the experimental ones.
publishDate 2012
dc.date.none.fl_str_mv 2012
2012-11-07
2013
2013-10-08
dc.type.none.fl_str_mv master thesis
http://purl.org/coar/resource_type/c_bdcc
NA
http://purl.org/coar/version/c_be7fb7dd8ff6fe43
dc.type.openaire.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
dc.identifier.none.fl_str_mv https://hdl.handle.net/2099.1/19192
url https://hdl.handle.net/2099.1/19192
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
Attribution-NonCommercial-ShareAlike 3.0 Spain
http://creativecommons.org/licenses/by-nc-sa/3.0/es/
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
Attribution-NonCommercial-ShareAlike 3.0 Spain
http://creativecommons.org/licenses/by-nc-sa/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universitat Politècnica de Catalunya
publisher.none.fl_str_mv Universitat Politècnica de Catalunya
dc.source.none.fl_str_mv reponame:UPCommons. Portal del coneixement obert de la UPC
instname:Universitat Politècnica de Catalunya (UPC)
instname_str Universitat Politècnica de Catalunya (UPC)
reponame_str UPCommons. Portal del coneixement obert de la UPC
collection UPCommons. Portal del coneixement obert de la UPC
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869408102505250816
score 15,300719

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