8 papers
Mapping the Turn: An Eulerian Binormal-Axis Diagnostic for Recirculating 3D Flows
John Marshall Cooper, Wen Wu
Three-dimensional (3D) recirculating flows are often interpreted qualitatively from selected streamline visualizations. In separated flows, such recirculating motion is central to…
Non-equilibrium effects in turbulent boundary layers over riblets: DNS of step changes in surface texture
Vishal Kumar, Melissa Kozul, Wen Wu +2
We computationally study the response of zero-pressure-gradient (ZPG) turbulent boundary layers (TBLs) to streamwise step changes from a smooth wall to riblets (SM_RI), and vice ve…
Leveraging unstructured grids for direct numerical simulations of wall turbulence
Amirreza Rouhi, Vishal Kumar, Wen Wu +2
Towards computational cost saving for direct numerical simulations (DNSs) of wall turbulence, we formulate an unstructured grid-generation framework, termed -grid, where the wa…
Drag penalty during relaminarization and Kelvin-Helmholtz-promoted retransition in an accelerating turbulent boundary layer over initially drag-reducing riblets
Benjamin Savino, Wen Wu
Direct numerical simulations of an accelerating turbulent boundary layer (TBL) over a smooth wall and a wall fully covered with streamwise-aligned riblets are performed to investig…
Improving boundary-layer separation prediction by an IDDES turbulence model using a pressure-gradient sensor
Benjamin S. Savino, Kevin Patrick Griffin, Bumseok Lee +3
This work extends a pressure-gradient sensor for boundary-layer separation originally developed for the shear-stress transport Reynolds-averaged Navier-Stokes (RANS) model (…
Attached Decelerating Turbulent Boundary Layers over Riblets
Benjamin S. Savino, Amirreza Rouhi, Wen Wu
Turbulent boundary layers over riblets subjected to adverse pressure gradients (APGs) are investigated by direct numerical simulation. Multiple APG strengths and riblet sizes are e…