The aim of this test case is to validate the following parameters of laminar transient multiphase flow with a prereferenced case [1]:
The mesh was created locally using the blockMesh tool and then imported on to the SimScale platform.
Import validation project into workspace
The domain of interest is a 2dimensional rectangular space 2 m
$2\text{}m$high and 1 m
$1\text{}m$wide as shown in Fig.1.
A uniformlyspaced hexahedral mesh was generated using the blockMesh tool (see Fig.2.). In order to keep the flow twodimensional, the mesh was designed to have only one layer in the y
$y$direction.
Tool Type : OPENFOAM®
Analysis Type : Multiphase (Laminar)
Mesh and Element types :
Mesh type  Cells in x  Cells in y  Cells in z  Number of nodes  Type 

snappyHexMesh  120  240  1  28800  2D hex 
Fluids:
The domain is filled with fluid f1
${f}_{1}$(see Table 2). A bubble of fluid f2
${f}_{2}$with diameter 0.5 m
$0.5\text{}m$is placed at t=0
$t=0$in the domain at a height of 0.5 m
$0.5\text{}m$(with bubble center as reference) on the central vertical line. Two cases are then simulatedwith different fluid properties as per [1]. Gravity was assumed to be 0.98 ms−2
$0.98\text{}m{s}^{2}$in the negative y
$y$direction.
Case  rho1
$rh{o}_{1}$

rho2
$rh{o}_{2}$

mu1
$m{u}_{1}$

mu2
$m{u}_{2}$

sigma
$sigma$


Case 1  1000
$1000$

100
$100$

10
$10$

1
$1$

24.5
$24.5$

Case 2  1000
$1000$

1
$1$

10
$10$

0.1
$0.1$

1.96
$1.96$

Boundary Conditions:
Parameter  Top and Bottom (A,B)  Left and Right (C,D)  Front and Back (E,F) 

Velocity  0.0 ms−1
$0.0\text{}m{s}^{1}$

Slip  Empty 
Pressure  Fixed Flux Pressure (0)
$(0)$

Fixed Flux Pressure (0)
$(0)$

Empty 
Phase Fraction  Zero Gradient  Zero Gradient  Empty 
A comparison of the bubble profiles for the two cases with the referenced case solutions is given in Fig.3. below.
Fig.3. Visualization of Bubble Profiles and comparison with reference for case 1 (left) and case 2 (right)
Shown in Fig.4. are graphs for the development of bubble center of mass and bubble velocity over time compared with referenced results.
Fig.4. Development of bubble center of mass and bubble velocity over time compared with referenced results.
[1]  (1, 2) FeatFlow Benchmark Suite: Rising Bubble 
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