In this paper we present a Direct Numerical Simulations (DNS) of channel flow with stationary and moving walls. Three cases, Poiseuille-type with U(W)/U(b) = 0.75, intermediate-type with U(W)/U(b) = 1.215, and Couette-type with U(W)/U(b) = 1.5 (U(W) and U(b) are the wall and the bulk velocity), were compared with the pure Poiseuille U(W)/U(b) = 0, at a bulk Reynolds number equal to 4,800 corresponding to Re(tau) = 288. The DNS results were used to scrutinize the capabilities of zeta-f eddy viscosity model (based on the elliptic relaxation concept) in reproducing the near-wall turbulence in non conventional flows where the shear stress structures are strongly different with respect to the cases used for models calibration. The zeta-f model (also in its basic formulation) demonstrated to have good prospects to reproduce the main phenomenology of such class of flows due to its built-in capabilities to account separately for the different (and opposite) near wall effects on turbulence: the damping due to viscosity and pressure reflection. The results of the computations demonstrated that standard zeta-f model can reasonably reproduce the phenomenology of these flows in terms of velocity and turbulent kinetic energy profiles and budgets.

DNS Scrutiny of the zeta-f Elliptic-Relaxation Eddy-Viscosity Model in Channel Flows with a Moving Wall / Borello, Domenico; Orlandi, Paolo. - In: FLOW TURBULENCE AND COMBUSTION. - ISSN 1386-6184. - STAMPA. - 86:2(2011), pp. 295-309. [10.1007/s10494-010-9323-y]

DNS Scrutiny of the zeta-f Elliptic-Relaxation Eddy-Viscosity Model in Channel Flows with a Moving Wall

BORELLO, Domenico;ORLANDI, Paolo
2011

Abstract

In this paper we present a Direct Numerical Simulations (DNS) of channel flow with stationary and moving walls. Three cases, Poiseuille-type with U(W)/U(b) = 0.75, intermediate-type with U(W)/U(b) = 1.215, and Couette-type with U(W)/U(b) = 1.5 (U(W) and U(b) are the wall and the bulk velocity), were compared with the pure Poiseuille U(W)/U(b) = 0, at a bulk Reynolds number equal to 4,800 corresponding to Re(tau) = 288. The DNS results were used to scrutinize the capabilities of zeta-f eddy viscosity model (based on the elliptic relaxation concept) in reproducing the near-wall turbulence in non conventional flows where the shear stress structures are strongly different with respect to the cases used for models calibration. The zeta-f model (also in its basic formulation) demonstrated to have good prospects to reproduce the main phenomenology of such class of flows due to its built-in capabilities to account separately for the different (and opposite) near wall effects on turbulence: the damping due to viscosity and pressure reflection. The results of the computations demonstrated that standard zeta-f model can reasonably reproduce the phenomenology of these flows in terms of velocity and turbulent kinetic energy profiles and budgets.
2011
budgets; dns; elliptic relaxation closures; turbulent channels with a moving wall
01 Pubblicazione su rivista::01a Articolo in rivista
DNS Scrutiny of the zeta-f Elliptic-Relaxation Eddy-Viscosity Model in Channel Flows with a Moving Wall / Borello, Domenico; Orlandi, Paolo. - In: FLOW TURBULENCE AND COMBUSTION. - ISSN 1386-6184. - STAMPA. - 86:2(2011), pp. 295-309. [10.1007/s10494-010-9323-y]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/344875
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