Previous Up Next

3.2  PASS: Time-reversed VOF advection in a shear flow

Author
Stéphane Popinet
Command
sh shear.sh shear.gfs
Version
091022
Required files
shear.gfs (view) (download)
shear.sh norms.ref
Running time
43 seconds

A test case initially presented by Rudman [27]. A circular patch of tracer is advected in a vortical shear flow. At t = 2.5 the flow direction is reversed. An exact advection scheme would restore the initial circular shape at t = 5.

The VOF (Volume-Of-Fluid) advection scheme is not exact. The initial, intermediate and final shape of the interface are represented on Figure 35. Figure 36 illustrates the error between the initial and final shapes. The corresponding error norms are given in Table 1.

Adaptive refinement is used with the gradient of the volume fraction as criterion. Eight levels of refinement are used on the interfaces and six away from the interface.


Figure 35: Volume fraction field at times (a) 0, (b) 2.5 and (c) 5.
(a)(b)(c)


Figure 36: Difference between the initial and final volume fraction fields.


Table 1: Norms of the error between the initial and final fields. The reference values are given in blue.
L1L2L
1.734e-045.716e-033.770e-01
1.734e-045.716e-033.770e-01

3.2.1  PASS: Time-reversed advection with curvature-based refinement

Author
Stéphane Popinet
Command
sh ../shear.sh curvature.gfs | gfsview-batch2D curvature.gfv
Version
091022
Required files
curvature.gfs (view) (download)
../shear.sh norms.ref curvature.gfv
Running time
14 seconds

Same as the previous test but with adaptivity based on the local curvature of the interface (with a maximum of eight levels of refinement).


Figure 37: Interface shape and refined mesh at time 2.5.


Figure 38: Difference between the initial and final volume fraction fields.


Table 2: Norms of the error between the initial and final fields. The reference values are given in blue.
L1L2L
1.021e-031.143e-026.401e-01
1.021e-031.143e-026.401e-01


Previous Up Next