[swordw7]

Hello everyone,
I am trying to establish the 2D counterflow diffusion flame by using Converge. But I failed to simplify the geometry model. Can I simplify the geometry model as a wedge for computation. And I also want to know how to define the boundary type.
Best wishes.

[Dan.Maciejewski]

In CONVERGE, we can simulate a wedge of the domain. In CONVERGE Studio, please see 2.4 Example Cases > Internal Combustion Engines > Heavy Duty Diesel > Engine_sector_Diesel_SAGE

This example is an engine sector, but the concept of using a wedge domain to simulate an axisymmetric flow / combustion problem is not limited to engines. To use this technique, periodic boundary conditions are applied to the boundaries adjacent to the non-modeled domain.

Also refer to CONVERGE User Manual > Boundary Conditions > PERIODIC Boundary Type

Modeling a wedge of the domain is appropriate only if the flow, and combustion / spray (if present) are approximately axisymmetric. The wedge approach allows swirl (flow out one periodic boundary and back in the other side), but cannot capture tumble correctly, since it is a 3D phenomenon. In CONVERGE 2.4 and earlier versions, the wedge axis must be the z-axis, and the wedge must be symmetric about the x-axis.

It would be advisable to first run your case with a fully 3-dimensional domain. If with sufficient grid resolution the three dimensional effects are very small, then try the wedge approach, say with a 90 degree wedge. If the flow / combustion results are sufficiently similar on the fully 3D and wedge cases, then this would indicate the wedge approach is valid.

[swordw7]

Originally Posted by Dan.Maciejewski

In CONVERGE, we can simulate a wedge of the domain. In CONVERGE Studio, please see 2.4 Example Cases > Internal Combustion Engines > Heavy Duty Diesel > Engine_sector_Diesel_SAGE

This example is an engine sector, but the concept of using a wedge domain to simulate an axisymmetric flow / combustion problem is not limited to engines. To use this technique, periodic boundary conditions are applied to the boundaries adjacent to the non-modeled domain.

Also refer to CONVERGE User Manual > Boundary Conditions > PERIODIC Boundary Type

Modeling a wedge of the domain is appropriate only if the flow, and combustion / spray (if present) are approximately axisymmetric. The wedge approach allows swirl (flow out one periodic boundary and back in the other side), but cannot capture tumble correctly, since it is a 3D phenomenon. In CONVERGE 2.4 and earlier versions, the wedge axis must be the z-axis, and the wedge must be symmetric about the x-axis.

It would be advisable to first run your case with a fully 3-dimensional domain. If with sufficient grid resolution the three dimensional effects are very small, then try the wedge approach, say with a 90 degree wedge. If the flow / combustion results are sufficiently similar on the fully 3D and wedge cases, then this would indicate the wedge approach is valid.

Thank you very much. I will try it.