|
Título:
|
Marginally turbulent flow in a square duct
|
|
Autores:
|
Uhlmann, Markus ;
Pinelli, Alfredo ;
Kawahara, Genta ;
Sekimoto, Atshushi
|
|
Tipo de documento:
|
texto impreso
|
|
Editorial:
|
Cambridge University Press, 2007
|
|
Dimensiones:
|
application/pdf
|
|
Nota general:
|
info:eu-repo/semantics/openAccess
|
|
Idiomas:
|
|
|
Palabras clave:
|
Estado = Publicado
,
Materia = Ciencias: Física
,
Tipo = Artículo
|
|
Resumen:
|
A direct numerical simulation of turbulent flow in a straight square duct was performed in order to determine the minimal requirements for self-sustaining turbulence. It was found that turbulence can be maintained for values of the bulk Reynolds number above approximately 1100, corresponding to a friction-velocity-based Reynolds number of 80. The minimum value for the streamwise period of the computational domain is around 190 wall units, roughly independently of the Reynolds number. We present a characterization of the flow state at marginal Reynolds numbers which substantially differs from the fully turbulent one: the marginal state exhibits a four-vortex secondary flow structure alternating in time whereas the fully turbulent one presents the usual eight-vortex pattern. It is shown that in the regime of marginal Reynolds numbers buffer-layer coherent structures play a crucial role in the appearance of secondary flow of Prandtl's second kind.
|
|
En línea:
|
https://eprints.ucm.es/id/eprint/21860/1/Pinelli02libre.pdf
|
