SLOW-DOWN OF NONLINEARITY IN 2-D NAVIER-STOKES FLOW

• Type: Article in International Scientific Journal
• Date: 1994

Authors

Gama, S (Author) FEUP; Vergassola, M (Author) Other

Journal

Title: Physica D: Nonlinear Phenomena

Vol. 76

Pages: 291-296

ISSN: 0167-2789

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 1 Citation

Other information

Authenticus ID: P-001-JPJ

DOI: 10.1016/0167-2789(94)90265-8

Resumo (PT): The equations governing the dynamics of large-scale perturbations superimposed on incompressible small-scale flow driven by a force have, under suitable conditions, the same structure as Navier-Stokes equations. The breaking of Galilean invariance due to the presence of the small-scale flow will, in general, induce a ¿vertex renormalization¿: the constant a in front of the advective nonlinearity does not remain equal to unity. A class of basic flows where the calculation of a a can be performed analytically is discussed. For finite Reynolds numbers, the constant a can indeed be very different from unity and can also vanish. The Reynolds number and the dynamics of a large-scale flow can then be quite different than predicted by setting a=1.

Abstract (EN): The equations governing the dynamics of large-scale perturbations superimposed on incompressible small-scale flow driven by a force have, under suitable conditions, the same structure as Navier-Stokes equations. The breaking of Galilean invariance due to the presence of the small-scale flow will, in general, induce a 'vertex renormalization': the constant a in front of the advective nonlinearity does not remain equal to unity. A class of basic flows where the calculation of a can be performed analytically is discussed. For finite Reynolds numbers, the constant a can indeed be very different from unity and can also vanish. The Reynolds number and the dynamics of a large-scale flow can then be quite different than predicted by setting a = 1.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6