Adaptive downstream tensorial eddy viscosity for hybrid large‐eddy simulations‐Reynolds‐averaged‐Navier–Stokes simulations. (2nd February 2021)

• Record Type: Journal Article
• Authors: Zhang, Wanjia; Shih, Tom I‐P.
• Is Part Of: International journal for numerical methods in fluids. Volume 93:Number 6(2021)
• Page Start: 1825
• Page End: 1842
• Publication Date: 2021-02-02
• Subjects: anisotropic RANS models -- embedded LES -- hybrid LES‐RANS -- Interface conditions -- turbulence modeling -- viscosity reconstruction; Fluid dynamics -- Mathematics -- Periodicals; 532
• DOI: 10.1002/fld.4954
• Languages: English
• ISSNs: 0271-2091

Abstract

Abstract : An adaptive method is developed to improve the accuracy of eddy‐viscosity Reynolds‐averaged‐Navier–Stokes (RANS) model in hybrid large‐eddy simulations (LES)‐RANS simulations by using available upstream LES results. The method first gets the tensorial eddy viscosity from the upstream LES solution at the LES‐RANS interface and then uses that information to improve the downstream RANS model by invoking the weak‐equilibrium assumption. The proposed method was evaluated via two test problems—flow in a channel and over a periodic hill. Results obtained show the proposed approach to increase the accuracy and stability of hybrid LES‐RANS simulations. Since the modification of the downstream RANS model is based on the tensorial eddy viscosity from the upstream LES solution, the method is adaptive to the problem being studied. Abstract : An adaptive method is developed to improve the accuracy of eddy‐viscosity RANS model in hybrid LES‐RANS simulations by using available upstream LES results. The method first gets the tensorial eddy viscosity from the upstream LES solution at the LES‐RANS interface and then uses that information to improve the downstream RANS model. Since the modification of the downstream RANS model is based on the tensorial eddy viscosity from the upstream LES solution, the method is adaptive to the problem being studied