Tagged: turbulencemodel


August 25, 2022 at 10:28 amuceczw4Subscriber
I find there is a possibe mistake in the source term of the transport equation of the turbulent kinetic energy dissipation rate (turbulence disperse model) (Eq. 14.378) when the Simonin model (Eq. 14.406) is used in the fluent theory guide . The alfa and density should not be multiplied in the last term at the righthand side of Eq. 14.378 according to the article they referred.

August 29, 2022 at 6:28 amDrAmineAnsys Employee
I will need to check the original article referenced in the paper. Do you have some screenshots you can share here?

August 30, 2022 at 8:09 amuceczw4Subscriber
**The referenced articles are:
Enwald, H., Peirano, E., Almstedt, A.E., 1996. Eulerian twophase flow theory applied to fluidization. International journal of multiphase flow 22, 2166.
Peirano, E., Leckner, B., 1998. Fundamentals of turbulent gassolid flows applied to circulating fluidized bed combustion. Progress in energy and combustion science 24, 259296.

August 30, 2022 at 9:13 amDrAmineAnsys Employee
Thanks. I will check.

September 6, 2022 at 3:43 pmDrAmineAnsys Employee
I checked the paper you are referring to but it did not have the same equations numbering. Step back to the TKE Equation before going to the Dissipation .Just look to this term from the paper of Enwald:
it is just added to the TKE equation of gas phase without getting multiplied with volume fraction. This is not the case in Fluent where the term get multiplied with alpha_g*rho_g and it has that already in the formulation.
Please explain which equations are you referring to and how you did the derivation.

September 8, 2022 at 3:16 pmuceczw4Subscriber
Actually, the issue we're talking about is the transport equation of the turbulent kinetic energy dissipation rate rather than the TKE equation. So, instead of Eq. [122], you should refer to Eq. [123124] in the article by Enwald et al. (the same as Eq. (151) in the article by Peirano and Leckner).
The source of dissipation in Fluent theory guide is defined as:
Note that the whole term at the righthand side of the equation i represents the source term.
In the article, it is defined as
Please read carefully the figures in the last reply, and you can find the details of the derivation and comparison.

September 9, 2022 at 11:45 amDrAmineAnsys Employee
I am reading carefully the figure and I ask to also check the definition of the TKE source term in the paper too. The source term of TKE is aslo different. In your explanation you are assuning both are using the same formulation for TKE source term which is wrong.

September 9, 2022 at 1:45 pm

September 9, 2022 at 1:56 pmDrAmineAnsys Employee
So the TKE term itself is different: Kp/alpha_c*rho_c is not equalt to alhpa_c*rho_c/tau_cp.

 You must be logged in to reply to this topic.
Simulation World 2022
Check out more than 70 different sessions now available on demand. Get inspired as you hear from visionary companies, leading researchers and educators from around the globe on a variety of topics from lifesaving improvements in healthcare, to bold new realities of space travel. Take a leap of certainty and check out a session today here.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Ansys Blog
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.
 Suppress Fluent to open with GUI while performing in journal file
 Heat transfer coefficient
 What are the differences between CFX and Fluent?
 Floating point exception in Fluent
 Time Step Size and Courant Number
 Difference between Kepsilon and Komega Turbulence Model
 The solver failed with a nonzero exit code of : 2
 Meshing
 Floating point exception
 Exporting Data Results

1141

1104

499

412

204
© 2022 Copyright ANSYS, Inc. All rights reserved.