[Outbound]

Greetings,

I'm having some doubts on how to properly categorize the Explicit Algebraic Reynolds Stress Model (EARSM) when writing about turbulence models in my thesis. As the name implies, it seems to be categorized as a Reynolds Stress model, as that's how it's described in one thesis I'm quoting from, but as can be seen from this link in CFD-Online which cites this article (which is that same as in my original source), it's categorized not as an RSM, but as a Non-linear Eddy Viscosity turbulence model for RANS equations.

Am I right then to place the EARSM as a subsection of the RANS->Non-linear Eddy Viscosity model instead as a sub section of the RSM models, and perhaps even add a note to the error of the thesis I mentioned?

Best regards,

[Outbound]

OK, I was checking up on this and it seems like the original thesis I mentioned might be correct, and the CFD-Online link misleading.

According to this paper, EARSM is indeed an RSM model, non-linear, but RSM nonetheless (author calls them RSTM, for Reynolds Stress Transport Model), as the EARSM doesn't make use of the Boussinesq eddy viscosity concept:

This Explicit Algebraic Reynolds Stress Model (subsequently referred to as WJ-EARSM) is based on a recalibrated Launder, Reece and Rodi (LRR) RSTM [12], from which a fully explicit and self-consistent algebraic relation is derived.

I'm going ahead with this characterization, however if you have anything to add I'd appreciate it.

Best regards,

[sbaffini]

Sthephen B. Pope, Turbulent Flows, Chapter 11 Reynolds-stress and related models, Section 9.2 Nonlinear turbulent viscosity.

The main aspect to consider here is that the EARSM do not explicitly model an actual turbulent viscosity which then is used as only turbulent input to your momentum equations. They actually model the whole stress tensor. Still, using modeling assumption you can revert them even to classical linear viscosities.

[Outbound]

OK, so I'm confused as to how I should categorize this. Should I just keep it within a subsection of the RSM section (given that,as the quote I included states, it's a refinement of the LRR) and mention what you just said, relating it to non-linear models eddy viscosity models?

[sbaffini]

Originally Posted by Outbound

OK, so I'm confused as to how I should categorize this. Should I just keep it within a subsection of the RSM section (given that,as the quote I included states, it's a refinement of the LRR) and mention what you just said, relating it to non-linear models eddy viscosity models?

Well, if it was me, i would just include them in the RSM section. But, more in general, and also to be sure about what to write in it, I suggest you to consult the section of the Pope book I mentioned in the previous post.