Two phase modelling for industrial applications

1
Two phase modelling for industrial applications

• Prof A.E.Holdø R.K.Calay

2
A case study

• Multiphase flows
• Investigation into gravity based oil-water
  separator
• Using IPSA model
• Parametric studies
• A design tool

3
A typical separator
4
Flow mechanisms

• Liquid/liquid flow
• Density difference
• Gravitational force
• Viscosity difference
• Viscous shear

5
CFD Model
6
Boundary conditions

• Inlet wateroil 5050
• Velocity for the mixture -.25m/s
• Symmetry boundary conditions along y-z plane at
  x0
• Outlets free
• All other walls as no-slip walls

7
Mesh models
8
Comparison of velocity profiles for different
mesh models

• Variation of velocity at outlet2

9
Variation of oil volume fraction at outlet2
10
ResultsDistribution phase volume fraction at
x0, y-z plane
11
Velocity contours at y-z mid plane
12
Velocity-vectors at mid y-z plane
13
Velocity at various locations along the z-axis
14
Streamlines
15
Parametric comparisons
16
Water volume fraction for particle size .25mm
and 1mm
17
Different inlet velocity0.25m/s
0.5m/s
18
Oil volume fraction 0.25m/s
0.5m/s
19
Changing the weir height0.5m
0.805m
20
Conclusions

• Convergence is difficult compared to single phase
  
• Mesh, relaxation factor, initialisation affect
  the solution
• Good results for preliminary investigations
• Data needed for validation

21
Further Modifications

• Transient simulation
• Models for emulsification, coagulation and
  bubble formation
• Effect of solid particles