Flow and turbulent structures around simplified car models

External car aerodynamics study has great importance in overall car efficiency and ride stability, being a key element in successful automotive design. The flow over car geometries shows three dimensional and unsteady turbulent characteristics. Additionally, vortex shedding, flow reattachment and re...

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Detalles Bibliográficos
Autores: Aljure Osorio, David E., Lehmkuhl Barba, Oriol|||0000-0002-2670-1871, Rodríguez Pérez, Ivette María|||0000-0002-3749-277X, Oliva Llena, Asensio|||0000-0002-2805-4794
Tipo de recurso: artículo
Fecha de publicación:2014
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/23638
Acceso en línea:https://hdl.handle.net/2117/23638
https://dx.doi.org/10.1016/j.compfluid.2014.03.013
Access Level:acceso abierto
Palabra clave:Motor vehicles -- Aerodynamics
Fluid dynamics
Turbulence
Automotive aerodynamics
CFD
Challenging LES
Turbulence models
Variational multiscale method
Large-eddy simulation
Vehicles de motor -- Aerodinàmica
Dinàmica de fluids
Turbulència
Àrees temàtiques de la UPC::Enginyeria mecànica::Disseny i construcció de vehicles::Automòbils
Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids
Descripción
Sumario:External car aerodynamics study has great importance in overall car efficiency and ride stability, being a key element in successful automotive design. The flow over car geometries shows three dimensional and unsteady turbulent characteristics. Additionally, vortex shedding, flow reattachment and recirculation bubbles are also found around the bluff body. These phenomena greatly influence the lift and drag coefficients, which are fundamental for ride stability and energy efficiency, respectively. The aim of the present study is focused on the assessment of different LES models (e.g. VMS or SIGMA models), as well as to show their capabilities of capturing the large scale turbulent flow structures in car-like bodies using relative coarse grids. In order to achieve these objectives, the flow around two model car geometries, the Ahmed and the Asmo cars, is simulated. These generic bluff bodies reproduce the basic fluid dynamics features of real cars. First, the flow over both geometries is studied and compared against experimental results to validate the numerical results. Then, different LES models are used to study the flow in detail and compare the structures found in both geometries.