Observatorio de I+D+i UPM

Memorias de investigación
Communications at congresses:
Transition prediction in incompressible boundary layer with finite-amplitude streaks
Year:2015
Research Areas
  • Fluid mechanics,
  • Aeronautical engineering
Information
Abstract
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.
International
Si
Congress
6th Global Flow Instability and Control Symposium
960
Place
Hersonissos, Crete, Greece
Reviewers
Si
ISBN/ISSN
00-0000-000-0
Start Date
28/09/2015
End Date
02/10/2015
From page
1
To page
1
Abstracts of the 6th Global Flow Instability and Control Symposium
Participants
  • Autor: Juan Angel Martin Bautista (UPM)
  • Autor: Pedro Paredes Gonzalez (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Dinámica y estabilidad no lineal en ingeniería aeroespacial
  • Departamento: Matemática Aplicada a la Ingeniería Aeroespacial
S2i 2019 Observatorio de investigación @ UPM con la colaboración del Consejo Social UPM
Cofinanciación del MINECO en el marco del Programa INNCIDE 2011 (OTR-2011-0236)
Cofinanciación del MINECO en el marco del Programa INNPACTO (IPT-020000-2010-22)