[neginmondegari]

even i want to model the turbidity current in dam in 2D in sedFOAM and interFOAM , the computational cost is huge if I want to couple them?
I know if i modelthe turbidity current in dam in sedFOAM is wrong , because sedFOAM is for close surface , but if I model it in sedFOAM this fault is it noticable or can be ignore ?
if I model the turbidity current in dam in 2D in sedFOAM is computational cost reduce and the better choice?

[neginmondegari]

thanks for your response, i have a question. does sedFOAM has RNGkEpsilon model for RAS models?

[handsomedog]

Hi Julien,
I'm starting to use sedFoam and I am running the tutorials, 2Dscour. The tutorial has been run 2 days but I only got the modelling results from0s to 4.5s . I do not make any changes about this tutorial.
Could you please tell me about the runtime of this tutorial ? And can I change the number of processor when I run this tutorial ? I am not sure if I could use SedFoam to run my case because there are only 8 processors in my computer. Is it enouge to run a 3-D scour case using SedFoam?
I am looking forward your response!
Best regards!
Chunping

[Linxiangfeng]

Dear julienC,
I am now using the sedFoam to simulate scour induced by a tidal stream turbine and want to use fvOptions available in openFoam to represent a turbine. However, the sedFoam is not compatible with fvOptions I think. Could you please provide some ideas or tips on how to modify the sedFoam?

Thank you very much.
Xiangfeng

[mathiant]

Originally Posted by Linxiangfeng

Dear julienC,
I am now using the sedFoam to simulate scour induced by a tidal stream turbine and want to use fvOptions available in openFoam to represent a turbine. However, the sedFoam is not compatible with fvOptions I think. Could you please provide some ideas or tips on how to modify the sedFoam?

Thank you very much.
Xiangfeng

Xiangfeng,

You are right, for the moment sedFoam is not compatible with fvOptions.

If you want to incorporate one of its functionalities, I suggest that you check how it is incorporated in an other available solver having that functionality and include it in sedFoam in a similar way.

If you are happy with your implementation, you can make a pull request on github to submit your modification and potentially make it available for other sedFoam users.

Best regards,


Antoine M.

[ajusree]

Respected Sir,
I am doing my MS project work on river flow dynamics. In that, I wanted to simulate channel flow using sedfoam. Is it possible to do so?

Thank you.

[cyss38]

yes


Why not?

[ajusree]

Sir,
I have been trying to modify the sedfoam code of scour downstream of an apron tutorial. I wanted to simulate a river flow in 3D with erodible boundaries. So I kept a rectangular box in blockMeshDict and I gave river geometry as my initial condition in funkySetFieldsDict. But the code got terminated after some time even without reaching 1 sec. When I checked the log file, I found an abrupt rise in the values of some of the variables.

Could you please give me some suggestions to correct this?

[cyss38]

• reduce the time step
• refine the interface zone..

Do you have check the output fields just before it diverges?

[ajusree]

Sir,
I am attaching the log file before the code getting terminated. The time step I have chosen was 1e-06. And my mesh(rectangular block) is uniformly refined.


Thank you.

[mathiant]

Originally Posted by ajusree

Sir,
I am attaching the log file before the code getting terminated. The time step I have chosen was 1e-06. And my mesh(rectangular block) is uniformly refined.


Thank you.

Hi,

Sometimes the particulate pressure "pa" can become unstable and reach very high values making the simulation to crash.

You can try to decrease the particulate pressure relaxation coefficient relaxPa in the file constant/granularRheologyProperties by at least one order of magnitude.

This might solve your stability issue.

Antoine M.

[Linxiangfeng]

Originally Posted by mathiant

Hi,

Sometimes the particulate pressure "pa" can become unstable and reach very high values making the simulation to crash.

You can try to decrease the particulate pressure relaxation coefficient relaxPa in the file constant/granularRheologyProperties by at least one order of magnitude.

This might solve your stability issue.

Antoine M.

Hi mathiant,
I am testing sedFoam to simulation scour around a cylindrical pile these days. The simulation easily crashed if the turbulent suspension term is included (i.e set the SUS to 1 in the twophaseRASproperties). Does the term have to be included in the simulation ? or Are there any methods to run the tests with the term included?

Thank you if you can provide any ideas.

best regards,
Xiangfeng

[mathiant]

Originally Posted by Linxiangfeng

Hi mathiant,
I am testing sedFoam to simulation scour around a cylindrical pile these days. The simulation easily crashed if the turbulent suspension term is included (i.e set the SUS to 1 in the twophaseRASproperties). Does the term have to be included in the simulation ? or Are there any methods to run the tests with the term included?

Thank you if you can provide any ideas.

best regards,
Xiangfeng

Hi Xiangfeng,

The turbulent suspension term SUS is the inverse of the turbulent Schmidt number used to model the dispersion of particles by the turbulence. Its value should be parameterized depending on the flow conditions (value ranging from 1 to 3).

It controls the concentration profile of suspended sediment which can contribute to an important fraction of the total sediment flux so it should be carefully chosen.

An empirical expression was given by Van Rijn (1984) in his paper dealing with suspended load:

SUS = 1 + 2*(ws/u*)^2

with ws the particles fall velocity and u* the bed friction velocity.

If you have stability issues, I also suggest that you try to reduce the timestep, refine the mesh where there are strong concentration gradients (at the interface) and maybe modify the coefficient relaxPa if you are using Mu(I) rheology as mentioned in the previous posts.

Antoine M.

[ajusree]

Hello Sir,
I have been trying to simulate flow in a river confluence with erodible bank material using sedFOAM. I modified the 2DScour example accordingly. The code starts to run, but after some time it got killed.

I am attaching the system folder and the boundary condition files. Kindly help me out if anybody knows the corrections which I should make in the code.




Thanks.
Ajusree

[JoostLinthorst]

Hi all, I am trying to implement a dynamic mesh in sedfoam. The model is of an object falling onto a sediment bed. So far every time I run the simulation, the simulation works up until sedFoam_rbgh is "Selecting FluidViscosityModel BoyerEtAl". After this step the solver stops without giving an error message.
Is it possible to implement a dynamic mesh in OpenFOAM?

[cyss38]

In OpenFoam yes it is possible (for example with pimpleFoam solver).

Regarding sedfoam, I started to look at how to do it but it is not yet implemented in the official version.


But do not hesitate to implement it and make a pull request :-)

[JoostLinthorst]

Hello Cyrille, thank you for your quick response. I'll admit that I have no experience or training in developing software, so if there is some other way in which this could be implemented, I would be very grateful.
I will spend some time on it now trying to implement it these next few days, any guidance would be much appreciated as well.

[songmuqing]

Hello Sir,

I have been trying to simulate the local scour around a pier in a river. The code has been successfully run, but the time step is too short, which will take a lot of time to simulate. Can I set different time steps for the flow phase and sediment phase to accelerate the simulation of sediment erosion？ And how to do it?

Thank you in advances.

[AlaaGhz]

hello sir.


I want to run a simulation on the formation of a scour so I am using the tutorial file 2DScour but I want to change the velocity profile and consider it as a wall jet, how can i implement the equation that I attached in an image file to the 2DScour tutorial.
note: The equation variable Y1/2 is the height where U = Um / 2 .


furthermore, is it possible to change the geometry and add a sluice gate at the entrance and leave the same velocity profile in the 2DScour before the gate and would the solver consider it after the sluice gate as a wall get instead of changing the whole equation? and input a flow rate on the openning of the gate?


just to note that I am new to OpenFOAM and SedFoam, and I hope that you can help.
thank you in advance.

[dalschouten]

Hi there, is it possible to edit the drag coefficients to an own equation? I am considering a modelling approach with Microplastics using sedfoam.