Investigation of the near-wake flow topology of a simplified heavy vehicle using PANS simulations
Journal article, 2018

The near-wake flow topology of a ground transportation system (GTS) is investigated using partially-averaged Navier–Stokes (PANS) simulations at Re=2.7×104. Recent numerical investigations for the GTS model using large eddy simulations (LES) showed an anti-symmetric flow topology (flow state II) in the vertical midplane compared to that observed in previous experimental studies (flow state I). The geometrical configuration of the GTS permits bi-stable behaviour, and the realisation of each of the two flow states, which are characterised by an asymmetrical flow topology, is achieved by varying the differencing scheme for the convective flux in the PANS simulations; AVL SMART schemes predict flow state I, while central differencing scheme (CDS) predicts flow state II. When the GTS model was placed away from the ground plane, the AVL SMART scheme fails to predict the flow asymmetry resulting in a pair of symmetrical vortices in the vertical midplane, while flow state II topology is observed when CDS is used. The switch from flow state I (II) to flow state II (I) is achieved by changing the numerical scheme from AVL SMART (CDS) to CDS (AVL SMART), with an intermediate transient-symmetric (TS) state being observed during the switching process. The numerical scheme in the PANS simulations thus plays a critical role in determining the initial flow topology in the near wake of the GTS.

Heavy vehiclesWakesBi-stabilityHybrid RANS-LES

Author

Anirudh Narayan Rao

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Guglielmo Minelli

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Jie Zhang

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Branislav Basara

Chalmers, Mechanics and Maritime Sciences

Sinisa Krajnovic

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Journal of Wind Engineering and Industrial Aerodynamics

0167-6105 (ISSN)

Vol. 183 243-272

Subject Categories

Geophysical Engineering

Ocean and River Engineering

Fluid Mechanics and Acoustics

Areas of Advance

Transport

Energy

DOI

10.1016/j.jweia.2018.09.019

More information

Latest update

11/28/2018