Flow around a single cube (2005)

First & Second sequence: Flow around a single cube (2005)

Project: High Resolution LES of Turbulent Flow in the Vicinity of Buildings including Thermal Effects Responsible: Marcus Letzel Description: This animation shows the turbulent flow field generated by a single cube with an edge length of 50m. The initial flow is laminar (from left) with a mean speed of 1 m/s, and neutrally stratified. The particle color displays the height above ground (red: high, blue: low). The wake vortex behind the building is especially dominant. The side view also shows the evolution of a roof vortex. Since cyclic boundary conditions along x and y are used, the turbulence generated on the lee side of the building hits the building again from the luv side after some time. Model Setup Total domain size (x|y|z): 960m x 320m x 150m Grid spacing (x|y|z): 5m x 5m x 5m Number of grid points (x|y|z): 192 x 64 x 30 Simulated time: 1h CPU-time: 155s Number of CPUs: 8 Machine/ processor type: NEC-SX6 Visualization software: DSVR Download Video Format File size Flash (.flv) 6.5mb Download MPEG (.avi) 6.5mb Download Flash (.flv) 7.2mb Download (side view) MPEG (.avi) 7.8mb Download (side view)

---

LES of a city quarter of Hanover (Allianz tower, 2006)

Allianz tower (2006)

Project: none Responsible: Siegfried Raasch? Description: Turbulent flow around a city quarter of Hannover. The mean flow is from west (right) with a speed of 1 m/s (neutral stratification is assumed). Clouds of particles are periodically released in front of the large building (Allianz tower) and in the courtyard of another complex of buildings. The particle color reflects the height above ground (red: high, blue: low). Topography data are from laser altimeter measurements (kindly provided by the Institut für Kartographie und Geoinformatik, Leibniz Universität Hannover). The resolution of the laser data allows to resolve cars on the street west of the Allianz building, staying there because of a red traffic light. The sequence shows that the turbulent flow within street canyons is highly variable so that flow directions may change completely within short times. Model Setup Total domain size (x|y|z): 256m x 256m x 200m Grid spacing (x|y|z): 1m x 1m x 1m Number of grid points (x|y|z): 256 x 256 x 200 Simulated time: 1h CPU-time: 1800s Number of CPUs: 32 Machine/ processor type: IBM-Regatta / Power4 Visualization software: DSVR Download Video Format File size Flash (.flv) 8.3mb Download MPEG (.avi) 8.3mb Download