[ncl94]

Hello everyone,

I am a new user of OpenFOAM and while watching some video and tutorials, I came across the PISO solver. The user guide's webpage says that the PISO solver offers turbulence modeling, with the following options: Laminar, RANS or LES. I am quite confused of what is the "laminar" model. Does it simulate the full momentum equation, like DNS?

[Severus]

Hello,
With the laminar model, we solve the original momentum equation that is not subject to any Reynolds averaging. Indeed as you mentioned, this is similar to DNS. Since there is no averaging involved, there are no Reynolds stresses that appear in the momentum equations (that have to be modelled). Hence, those terms will be zero.

You can also take a look at the code, to understand the implementation. Check the source code (.H file) - https://www.openfoam.com/documentati...8H_source.html
In lines 164 to 187, please see the comments that are provided.

And the corresponding (.C file) - https://www.openfoam.com/documentati...8C_source.html
In lines 188 to 329, we see that zero is returned for all the turbulent quantities except nuEff, where nu (molecular viscosity) is returned, thereby solving the original momentum equation.

Thanks