A new formulation of fk for the PANS model
Artikel i vetenskaplig tidskrift, 2019

The partially averaged Navier–Stokes (PANS) model, proposed in Girimaji [Partially-averaged Navier-Stokes model for turbulence: a Reynolds-averaged Navier-Stokes to direct numerical simulation bridging method. ASME J Appl Mech. 2006;73(3):413–421], can be used to simulate turbulent flows either as a RANS, LES or DNS. The PANS model includes fk which denotes the ratio of modelled to total kinetic energy. In RANS, fk = 1, and in DNS it goes to zero. In the present study we propose a new formulation for fk based on the H-equivalence introduced by Friess et al. [Toward an equivalence criterion for hybrid RANS/LES methods. Int J Heat Fluid Flow. 2015;122:233–246]. In this formulation the expression of fk is derived to mimic DES. This new formulation behaves very much like classic DES, even though the two formulations use different mechanisms to separate modelled and resolved scales. They show very similar performance in separated flows as well as in attached boundary layers. Moreover, the new formulation exhibits similar robustness features as DES.

hump flow

DES

hill flow

PANS

LES

channel flow

Författare

Lars Davidson

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Christophe Friess

Aix-Marseille Université

Journal of Turbulence

14685248 (eISSN)

Vol. 20 5 322-336

Ämneskategorier

Teknisk mekanik

Beräkningsmatematik

Strömningsmekanik och akustik

DOI

10.1080/14685248.2019.1641605

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Senast uppdaterat

2020-02-18