DdQq descriptors’ field types

[hhan]

Hello,

I am working on a simulation of flow problems in porous media and have been referring to the example porousPoiseuille2d. I noticed that the code uses several different descriptors like:

typedef D2Q9<FORCE, EPSILON, K, NU, BODY_FORCE> DESCRIPTOR;
typedef D2Q9<POROSITY> DESCRIPTOR;
typedef D2Q9<> DESCRIPTOR;

I read through the source code, but I’m still unclear about the meaning of these field types and how they differ. Could someone explain the distinction between them and provide guidance on how to choose the right field for a simulation?

Key Points:
What is the role of these field types in the simulation?
What differences exist between D2Q9<FORCE, EPSILON, K, NU, BODY_FORCE>, D2Q9<POROSITY>, and D2Q9<>?
How should I choose the right descriptor for simulating flow in porous media?

Thanks in advance!

[Adrian]

Basic information on the descriptor concept is available in our user guide (Section 2.1).

The descriptor aliases you posted are identical in all but their declared fields (cf. user guide on OpenLB’s field concept). All this means in the end is that the stated fields will be pre-allocated and automatically communicated. Their declaration here is mostly for documentation on the required data of the used LB models.

[hhan]

Thank you for your reply!

Are the default values for descriptor aliases velocity and rho?

And what is the meaning of the parameters x, y, and z in FIELD_BASE<x, y, z>? How do they influence the properties of the fields?

[Author]

Posts