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Memorias de investigación
Research Publications in journals:
Direct and adjoint global stability analysis of turbulent transonic flows over a NACA0012 profile
Year:2014
Research Areas
  • Physics chemical and mathematical,
  • Fluyd dynamics,
  • Engineering
Information
Abstract
In this work, various turbulent solutions of the two-dimensional (2D) and three-dimensional compressible Reynolds averaged Navier?Stokes equations are analyzed using global stability theory. This analysis is motivated by the onset of flow unsteadiness (Hopf bifurcation) for transonic buffet conditions where moderately high Reynolds numbers and compressible effects must be considered. The buffet phenomenon involves a complex interaction between the separated flow and a shock wave. The efficient numerical methodology presented in this paper predicts the critical parameters, namely, the angle of attack and Mach and Reynolds numbers beyond which the onset of flow unsteadiness appears. The geometry, a NACA0012 profile, and flow parameters selected reproduce situations of practical interest for aeronautical applications. The numerical computation is performed in three steps. First, a steady baseflow solution is obtained; second, the Jacobian matrix for the RANS equations based on a finite volume discretization is computed; and finally, the generalized eigenvalue problem is derived when the baseflow is linearly perturbed. The methodology is validated predicting the 2D Hopf bifurcation for a circular cylinder under laminar flow condition. This benchmark shows good agreement with the previous published computations and experimental data. In the transonic buffet case, the baseflow is computed using the Spalart?Allmaras turbulence model and represents a mean flow where the high frequency content and length scales of the order of the shear-layer thickness have been averaged. The lower frequency content is assumed to be decoupled from the high frequencies, thus allowing a stability analysis to be performed on the low frequency range. In addition, results of the corresponding adjoint problem and the sensitivity map are provided for the first time for the buffet problem. Finally, an extruded three-dimensional geometry of the NACA0012 airfoil, where all velocity components are considered, was also analyzed as a Triglobal stability case, and the outcoming results were compared to the previous 2D limited model, confirming that the buffet onset is well detected.
International
Si
JCR
Si
Title
International Journal for Numerical Methods in Fluids
ISBN
1097-0363
Impact factor JCR
1,329
Impact info
ISI Journal Citation Reports © Ranking: 2013: 19/31 (Physics Fluids & Plasmas); 32/95 (Mathematics Interdisciplinary Applications); 58/102 (Computer Science Interdisciplinary Applications); 63/139 (Mechanics)
Volume
76
10.1002/fld.3929
Journal number
3
From page
147
To page
168
Month
SEPTIEMBRE
Ranking
Participants
  • Autor: Esteban Ferrer Vaccarezza (UPM)
  • Autor: Leo Miguel Gonzalez Gutierrez (UPM)
Research Group, Departaments and Institutes related
  • Creador: Departamento: Mecánica de Fluidos y Propulsión Aeroespacial
S2i 2020 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)