Memorias de investigación
Ponencias en congresos:
Transition prediction in incompressible boundary layer with finite-amplitude streaks
Año:2015
Áreas de investigación
  • Mecánica de fluidos,
  • Ingeniería aeronaútica
Datos
Descripción
Modulating the boundary layer velocity profile is a very promising strategy for achieving transition delay, and thus reducing the friction of the plate. An usual way to perform it is by perturbing the flow with counter-rotating vortices that exhibit transient, non-modal growth and lead to streamwise aligned streaks inside the boundary layer, which have been proved (theoretical and experimentally) to be very robust flow structures. Recently, a new mechanism of generating high amplitude streaks has been proposed, consisting on miniature vortex generators (MVGs), increasing considerably the potential stabilization effect. Hence, we propose a numerical tool to analyze the stability properties of the streaky flow without big computational resources. Since streaks depend on how they are generated, and it is linked to the geometric configuration of the surface, a cheap CPU numerical analysis is required in order to perform large parametric studies for streak optimization. For this end, we use the reduced Navier-Stokes (RNS) equations to simulate the nonlinear downstream evolution of finite amplitude streaks in incompressible boundary layer flow. Regarding the stability analysis, the linear three-dimensional Parabolized Stability Equations (PSE-3D) concept constitutes the best candidate for this task. Herein, we present a thorough parametric study of the instability characteristic with respect to critical conditions of the modified incompressible zero-pressure-gradient flat-plate boundary layer by means of finite-amplitude linearly optimal disturbances or streaks. The parameter space is extended from low- to high- amplitude streaks, accurately documenting the transition delay for low-amplitude streaks and the amplitude threshold for streak shear layer instability or bypass transition, which drastically displaces the transition front upstream.
Internacional
Si
Nombre congreso
6th Global Flow Instability and Control Symposium
Tipo de participación
960
Lugar del congreso
Hersonissos, Crete, Greece
Revisores
Si
ISBN o ISSN
00-0000-000-0
DOI
Fecha inicio congreso
28/09/2015
Fecha fin congreso
02/10/2015
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Título de las actas
Abstracts of the 6th Global Flow Instability and Control Symposium
Esta actividad pertenece a memorias de investigación
Participantes
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Grupo de Investigación: Dinámica y estabilidad no lineal en ingeniería aeroespacial
  • Departamento: Matemática Aplicada a la Ingeniería Aeroespacial