[TALEMWA EMMANUEL]

Hello,
I am simulating slug flow in annulus with inner pipe rotation using Ansys Fluent only. I have one inlet and one outlet.I would want to use velocity inlet specification. I have divided the inlet into 3 regions with air inlet at the centre and water inlets near the pipe walls, so that the volume fraction of a particular phase at an inlet is set to 1 and for the second phase is set to 0 . The outlet is maintained as a single zone.
Without dividing the geometry I can generate a hexahedral mesh using nodes at the outlet and inlet and applying the multizone method. I have attached it below

My problem is:
1. With When I divide the inlet as described above, the nodes on the inlet are slit up and I cant have a structured hexahedral mesh. Also, the multizone option in this case returns an error: "MultiZone found free block in swept body." Is there a better way of having two inlets on the same surface and still achieve a structured hexa mesh?

2. I decided to use an undivided inlet and specified mass flowrate at the inlet since it allows mass flow for both phases but it leads to low liquid holdup and high pressure drop values than the experimental results. Does this mean the mass flowrate is an inaccurate specification compared to velocity inlet since the domain is relatively incompressible or the difference could be from other reasons?
3. Is it possible to specify velocities of two phases on one inlet?

I would really appreciate your help.

[Far]

Originally Posted by TALEMWA EMMANUEL

Hello,
I am simulating slug flow in annulus with inner pipe rotation using Ansys Fluent only. I have one inlet and one outlet.I would want to use velocity inlet specification. I have divided the inlet into 3 regions with air inlet at the centre and water inlets near the pipe walls, so that the volume fraction of a particular phase at an inlet is set to 1 and for the second phase is set to 0 . The outlet is maintained as a single zone.
Without dividing the geometry I can generate a hexahedral mesh using nodes at the outlet and inlet and applying the multizone method. I have attached it below

My problem is:
1. With When I divide the inlet as described above, the nodes on the inlet are slit up and I cant have a structured hexahedral mesh. Also, the multizone option in this case returns an error: "MultiZone found free block in swept body." Is there a better way of having two inlets on the same surface and still achieve a structured hexa mesh?

2. I decided to use an undivided inlet and specified mass flowrate at the inlet since it allows mass flow for both phases but it leads to low liquid holdup and high pressure drop values than the experimental results. Does this mean the mass flowrate is an inaccurate specification compared to velocity inlet since the domain is relatively incompressible or the difference could be from other reasons?
3. Is it possible to specify velocities of two phases on one inlet?

I would really appreciate your help.

You can split volume along whole length and mesh it ansys meshing. You can do it in design modeller or spaceclaim.

For mesh you can use ICEMCFD without splitting volume