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The problems about the turbulentDFSEMinlet method for nonreacting jet 

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April 18, 2019, 13:30 
The problems about the turbulentDFSEMinlet method for nonreacting jet

#1 
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lgz
Join Date: Apr 2019
Posts: 4
Rep Power: 6 
Hi,
I have run a nonreacting case with the initial turbulent inlet boundary condition which was created by the turbulentDFSEM method. However, the results there are no velocity fluctuation (u') in the streamline. I don't know how to deal with this problem. I would appreciate any help on this matter. Thanks in advance! The cases including the files: 0/ were attached. The turbulentDFSEMinlet was introduced in this website: https://www.openfoam.com/releases/op...conditions.php 

January 27, 2020, 05:23 

#2 
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Marc
Join Date: May 2017
Posts: 42
Rep Power: 8 
Maybe it's a bit late but the line:
Code:
L uniform 0; If you used a precursor RANS simulation there are correlations to obtain L from you data. For example for a simulation you have that: You can find similar correlations for the model you employed. If you didn't get that data from a precursor RANS, I would suggest looking a twopoint correlations to obtain . 

May 20, 2020, 17:19 

#3 
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Xiangjie Wang
Join Date: Jul 2019
Posts: 26
Rep Power: 6 
Hi Marc,
I encountered the same problem. Could you please give me some suggestions on how to do the RANS precursor simulation? I set turbulentDFSEMInlet as my inlet velocity. My computational domain is a wind tunnel with a 50(streamwise)*27.5(width)*22.5(height). I have run my simulation with a uniform velocity inlet and the results showed that it could work. But when I changed my inlet boundary condition of U, it couldn't. After inputing blockMesh and decomposePar, I input: mpirun np 12 pisoFoam parallel. But it was stuck at the first time step, which showed: Time = 0.005 Courant Number mean: 0 max: 0 In my simulation, the simulation type is RAS, RAS model is KEpsilon. I only defined the mean velocity profile in ./constant/boundaryData/inlet directory, and for R and L, I set them to a fixed value. This is how my inlet boundary of U looks like: inlet { type turbulentDFSEMInlet; delta 12; nCellPerEddy 1; d 1; R uniform (0.5 0.1 0.1 0.03 0.01 0.01); L uniform 0.005; mapMethod nearestCell; value $internalField; } I will appreciate it if you can give me some suggestions! Thanks! Xiangjie 

July 20, 2023, 14:57 
turbulentDFSEMInlet gets stuck

#4  
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Alireza Maleki
Join Date: Aug 2017
Location: United State
Posts: 20
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Quote:
Hi Wang, It is late, but I have the same problem, it just got stuck in the first iteration and even it does not start making the turbulence and solving the velocity equation. my simulation is a LES and I gave the R, L, and U, and I'm using the turbulentDFSEMInlet with the following setup PHP Code:
PHP Code:


July 20, 2023, 15:35 

#5  
New Member
Xiangjie Wang
Join Date: Jul 2019
Posts: 26
Rep Power: 6 
Hi Alireza,
I guess you have found out how to solve the problem. You are using an old version of Openfoam, am I right? Quote:


July 20, 2023, 16:22 

#6 
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Alireza Maleki
Join Date: Aug 2017
Location: United State
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July 20, 2023, 16:24 

#7 
New Member
Xiangjie Wang
Join Date: Jul 2019
Posts: 26
Rep Power: 6 

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