Numerical Simulation of Flow Over Urban-Like Topographies and Evaluation of Turbulence Temporal Attributes
Abstract
We have used large-eddy simulation with an immersed boundary method to study turbulent flows over distributions of uniform height, staggered cubes. The computational domains were designed such that both the roughness sublayer and a region of the inertial layer are resolved. With this, we record vertical profiles of time series of fluctuating streamwise and vertical velocity at different locations throughout the domain. Contour images of these fluctuating quantities shown relative to elevation and time are studied; contour images of Reynolds shear stresses owing to sweeps and ejections are also studied. These images show that periods of momentum excess (deficit) in the inertiallayer precede excitation (subdual) of cube-scale coherent vortices in the roughness sublayer. We compute this time lag (termed advective lag) and demonstrate that it scales linearly with wall-normal elevation. The advective lag is attributed to coherent, low andhigh-momentum regions in the aloft inertial layer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 19, 2016
- Accession Number
- AD1000599
Entities
People
- Elie Bou-Zeid
- Qi Li
- William E Anderson
Organizations
- Baylor University