Validation of the LES approach in Kiva-3V on a square duct geometry

The LES approach implemented in the Kiva-3V code is evaluated on the fully developed flow through a rectangular duct of square cross section. The Reynolds number based on the bulk velocity and duct width is 8000. The number of grid nodes is 96 000. Three subgrid-scale models are compared: the Smagorinsky, the WALE and the Vreman model. The results differ mainly in the predicted shear stress levels. The Smagorinsky model shows a large overprediction of the shear at the walls, whereas both the WALE and Vreman models perform better due to a reduced contribution of the subgrid dissipation. In this study the WALE model gives the best results on simulating the secondary flows and turbulence statistics