The modification of the turbulent cascade by polymeric additives is addressed by direct numerical simulations of homogeneous isotropic turbulence of a FENE-P fluid. According to the appropriate form of the Karman-Howarth equation, two kinds of energy fluxes exist, namely the classical transfer term and the coupling with the polymers. Depending on the Deborah number, the response of the flow may result either in a pure damping or in the depletion of the small scales accompanied by increased fluctuations at large scale. The latter behaviour corresponds to an overall reduction of the dissipation rate with respect to an equivalent Newtonian flow with identical fluctuation intensity. The relevance of the position of the crossover scale between the two components of the energy flux with respect to the Taylor microscale of the system is discussed.

De Angelis, E., Casciola, C., Benzi, R., Piva, R. (2005). Homogenous isotropic turbulence in dilute polymers. JOURNAL OF FLUID MECHANICS, 531, 1-10 [10.1017/S0022112005003666].

Homogenous isotropic turbulence in dilute polymers

BENZI, ROBERTO;
2005-01-01

Abstract

The modification of the turbulent cascade by polymeric additives is addressed by direct numerical simulations of homogeneous isotropic turbulence of a FENE-P fluid. According to the appropriate form of the Karman-Howarth equation, two kinds of energy fluxes exist, namely the classical transfer term and the coupling with the polymers. Depending on the Deborah number, the response of the flow may result either in a pure damping or in the depletion of the small scales accompanied by increased fluctuations at large scale. The latter behaviour corresponds to an overall reduction of the dissipation rate with respect to an equivalent Newtonian flow with identical fluctuation intensity. The relevance of the position of the crossover scale between the two components of the energy flux with respect to the Taylor microscale of the system is discussed.
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore FIS/02 - Fisica Teorica, Modelli e Metodi Matematici
English
Con Impact Factor ISI
Additives; Computer simulation; Damping; Newtonian flow; Polymers; Deborah number; Dilute polymers; Homogenous isotropic turbulence; Polymeric additives; Turbulence; polymer
De Angelis, E., Casciola, C., Benzi, R., Piva, R. (2005). Homogenous isotropic turbulence in dilute polymers. JOURNAL OF FLUID MECHANICS, 531, 1-10 [10.1017/S0022112005003666].
De Angelis, E; Casciola, C; Benzi, R; Piva, R
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/37605
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