Flow over Periodic Hills

LES by Temmerman and Leschziner


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Flow Configuration

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Flow over 2D periodic hills consisting in polynomial-shaped obstacles mounted on a flat plate with recirculation region in their wake.

Geometry

The test case is relevant for studying near-wall or/and subgrid-scale modelling in LES in the presence of separation and reattachement.

The geometry retains the shape of the hill defined by Almeida (Case 18 ). As the true periodicity of the experiment (case 18-B) was in question during the 1995 ERCOFTAC/IAHR workshop, no reliable experimental data is available. So, the rest of the configuration has been modified for computing cost reasons.

The reference presented herein consists in a wall-resolving computation using the dynamic subgrid-scale model for a large-eddy simulation.

Geometrical Parameters

Flow Parameters

Simulation details

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Available LES Data

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Separation is predicted at x=0.22h and reattachment at x=4.72h. Typical mean stream lines are shown in the figure below.

figure

Profiles of the first component (U) and second (V) mean velocities, and corresponding rms velocities u', v' and u'v', and turbulent kinetic energy k are available at a number of y/h locations. All quantities are dimensionless (using the bulk velocity Ub).

Compressed archive of the files can be downloaded from the link below, or files can be retrieved individually from the table.

y/h file name Quantities
0.05 data-001 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
0.5 data-002 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
1.0 data-003 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
2.0 data-004 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
3.0 data-005 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
4.0 data-006 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
5.0 data-007 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
6.0 data-008 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
7.0 data-009 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2
8.0 data-010 y/h, U/Ub, V/Ub, u'u'/Ub2, v'v'/Ub2, u'v'/Ub2, k/Ub2

Previous and Reference Numerical Solutions

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Mellen et al. report the first LES on the case in 2000. They and later, Temmerman et al. have performed a serie of subgrid scale models and wall-treatment sensitivity by taking the LES results on a fine grid where no wall functions applied (data given herein) as a reference. The exact value of reattachement point varies with SGS model and grid. A priori tests can also be found in Jang et al.

Related Publications

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