SimScale CAE Forum

Modeling Chilled Water Piping


#22

@jousefm
Thank you so much for all your help! I really do appreciate it.

I am having some trouble viewing the results at the moment from the several simulations I have run.

This is the link to the one I am working on right now:
https://www.simscale.com/workbench/?pid=8655912107356716205

When I look at the convective heat transfer 5 and the simulation run 2. All i see is a blank page and nothing loads for me. I am wondering is there something wrong with my simulations or does it have to do something with the website?
Any help you can provide to me would be greatly appreciated!

Thanks,
Maria Chek


#23

Hi Maria and sorry for the late feedback!

Will check. Let me know if it worked for you in the meantime.

Edit: Everything works fine from my side. Can you check your internet connection please?

Cheers,

Jousef


#24

@jousefm,

Thank you so much for all your help.

I have couple of questions for you about SimScale model.

There are several different materials that can be used for pipes like steel or HDPE. Is there a way to specify in the model what kind of material of pipe it is?

Additionally, the friction in the pipes. Is there a way to control the friction in the pipe? Like make the pipe rough or smooth if needed?

Thank You so much for all your help!
Maria Chek


#25

Hi Maria,

Why would you want to change the material? For CHT it makes sense also regarding thermal conductivity and other parameters you want to specifiy. Other than that the material is irrelevant for a simple pipe flow simulation - at least I cannot think of a scenario where the material has an influence on a simple incompressible pipe flow simulation. @Get_Barried, feel free to jump in if you have an idea.

Regarding the roughness there should be an option if you set a custom boundary condition and change the turbulent kinetic energy (TKE) to wall function and set the sub option to rough at least to my knowledge. I’m at my smartphone in the tram at the moment and would have to check as soon as I am home but you can test it in the meantime :slight_smile:

Best,

Jousef


#26

@jousefm
Thank you for your quick response.
The reason why I am interested in different materials for pipes is because I am not sure which material the model in SimScale assumes it to be. Is there a default material that is assumed for the pipework?

I am also interested in the friction loss in the pipe because in the simulation results that I have compiled, no matter the configuration of the pipe work, it seems that the friction loss is very small for each case. I guess what am curious about is the default value for it and is there a factor by which i can increase it?
Thank you,
Maria Chek


#27

@jousefm,

I have one more question for you. I am attempting to specify the custom boundary conditions as you have suggested to me before. However I am running into couple of problems. I am not exactly sure what kind of setting I am supposed to specify for specific dissipation rate and turb. thermal diffusion. I don’t particularly have any knowledge of the specific values for those in my case and it doesn’t allow me to leave it as 2D empty.

while the periodic, wedge, and symmetry setting all deal with symmetry and I don’t believe they would work in my case. And when I did try them they failed as well.

Any guidance you can provide to me would be greatly appreciated,
Thank you,
Maria Chek


#28

Hi Maria!

So for fluid flow simulations (simple incompressible flow) there is no need to define material as mentioned before as this has no influence on the fluid behavior except if let’s say you do CHT or Fluid-Structure Interaction where the material properties would be relevant.

Materials used for your type can only be Newtonian, Non-Newtonian or a Viscosity Model.

Regarding your question about the parameters. You simply choose a custom BC and make the adaption as seen below.

For the turbulent BC this article will help you out: Defining Turbulent Boundary Conditions

The parameter for the roughness I have shown in the picture above will be adapted for reference data that you have. That’s actually an iterative process where you check first if the roughness constant of 0.5 works, if not then adapt and re-run. Hope it makes sense so far.

All the best!

Jousef