Abstract
Flow evolution in a rotating mixing layer is investigated using direct and large-eddy simulation. The mixing layer rotates about a fixed vertical axis perpendicular to the plane of its mean initial shear. The rotating mixing layer forms oscillatory large-scale columnar structures and rapid horizontal flow-reversals. The frequency of these oscillations varies approximately inversely with the Rossby number, $Ro$. At low $Ro$ vertical mixing of a passive scalar is strongly reduced. This is quantified by investigating the evolution of level-sets of the scalar field. The surface-area of the level-sets remains virtually constant even at modest rotation rates. More localized motions are less affected by rotation and yield comparatively high levels of surface-wrinkling. Rotation effects are accurately predicted in large-eddy simulations that involve the dynamic eddy-viscosity model or the LANS-$\alpha$ or Leray regularization models. The small-scale variability is best preserved when using the LANS-$\alpha$ formulation.
Original language | English |
---|---|
Title of host publication | Direct and Large-Eddy Simulation VI |
Editors | Eric Lamballais, Rainer Friedrich, Bernard J. Geurts, Olivier Métais |
Place of Publication | Dordrecht |
Publisher | Springer |
Pages | 249-256 |
Number of pages | 8 |
ISBN (Electronic) | 978-1-4020-5152-4 |
ISBN (Print) | 978-1-4020-4909-5 |
DOIs | |
Publication status | Published - Oct 2006 |
Event | 6th ERCOFTAC Workshop on Direct and Large-Eddy Simulation VI, DLES 2005 - University of Poitiers, Poitiers, France Duration: 12 Sep 2005 → 14 Sep 2005 Conference number: 6 |
Publication series
Name | ERCOFTAC series |
---|---|
Publisher | Springer |
Volume | 10 |
ISSN (Print) | 1382-4309 |
ISSN (Electronic) | 2215-1826 |
Conference
Conference | 6th ERCOFTAC Workshop on Direct and Large-Eddy Simulation VI, DLES 2005 |
---|---|
Abbreviated title | DLES |
Country | France |
City | Poitiers |
Period | 12/09/05 → 14/09/05 |
Keywords
- Direct numerical simulation
- Rotation rate
- Passive scalar
- Momentum thickness
- Rossby number