Learning Forum

[Rachit Bundiwal]

Hi i really need your help in Multiphase VOF simulation . Currently i am trying to validate a research paper on Pintle injector , the author used VOF modelling to simulate water and air interaction. using implicit velocity formulation ,  and surface tension force modelling . during the simulation the energy diverges . T also tried changing the URF's but still it does'nt work .Also during the initialisation the velocity is not showing.  I am attaching the SS of setup . Please help me..

[Rob]

What did you set as the inlet? What time step are you using? Did you use any patch regions?

[Rachit Bundiwal]

i am giving mass flux value to both the inlets ,and this simulation is a steady state simulation and no i am not using any patching regions . In paper they are running gas as compressible and water as incompressible can you tell me how to do that , do i need to write a UDF ?

[Hemant Gurav]

Yes, you can use UDFs or simply create expressions. 

[Rachit Bundiwal]

can you tell how to create a expression??

 

[Hemant Gurav]

Please go through Ansys Learning material, users guide and tutorials. Check for Compressible flow input conditions and How to create expressions.

[Hemant Gurav]

Can you check the inlet conditions please confirm is it velocity inlet or pressure inlet conditon etc,also check for the temperature conditions provided as energy equation is diverging)? Additionally you can check with different Pressure-Velocity couplings scheme for example SIMPLEC, PISO etc

[Rob]

I recommend reviewing the Learning materials for the material properties (and tutorials under Help in Fluent). That should help with your questions. 

[Rachit Bundiwal]

It's mass flow inlet and according to paper coupled scheme is used . I tried with many different schemes but then also energy is diverging. Temperature condition for both the inlets is 300 K