# MESHING turbulent pipe flow **URL:** \ **Category:** Project Support\ **Created:** [September 24, 2019, 10:49am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365 "2019-09-24T10:49:34Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 24, 2019, 10:49am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/1 "2019-09-24T10:49:34Z")
Hi! I am trying to replicate the following exercise: > **[Turbulent Flow Through Pipe | Validation Case | SimScale](https://www.simscale.com/docs/validation-cases/turbulent-pipe-flow/)** > > This SimScale validation case assesses incompressible steady-state turbulent models applied to water flow through a straight pipe. There are two different meshes but i canโ€™t make them. How can I develope it with the mesh controls ? I have already checked the link of the public project on Simscale. Thanks!!! ![](https://www.simscale.com/forum/uploads/default/original/3X/8/b/8b3463e166fc667011b369f97266657a399cc62e.png) ---
**Author:** ![HamzaBaig](https://www.simscale.com/forum/user_avatar/www.simscale.com/hamzabaig/32/61949_2.png) [@HamzaBaig](https://www.simscale.com/forum/u/HamzaBaig)\ **Post date:** [September 24, 2019, 11:16am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/2 "2019-09-24T11:16:04Z")
Hi @andrea_perez, Actually the Mesh preview is right, it is just a clip of the mesh somewhere along the pipe length. ![MESH%20CLIP](https://www.simscale.com/forum/uploads/default/original/3X/7/0/7068609c722dc641a214b1af4c5cea4c65da69f9.png) Just follow the procedure adopted in this link. > **[Turbulent Pipe Flow by dzivkovic | SimScale](https://www.simscale.com/projects/dzivkovic/turbulent_pipe_flow_validation/)** > > This project simulates turbulent flow through a straight circular pipe. Two turbulence models were used: kEpsilon and kOmegaSST. Simulation results from were validated using corresponding analytical expressions. | Simulation project by dzivkovic Regards ---
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 24, 2019, 11:26am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/3 "2019-09-24T11:26:47Z")
No, This is not fine, There are two ways to mesh this kind of flow problems, depending on the accuracy you need. if you need y+\<1 the wall layers have to be very thin, but if you need y+\>30, those layers can be more coarse. In both cases, the procedure of mesh (or the aspect of it) has to be the same. Does someone help me with this? This is my project. > **[SimScale Login](https://www.simscale.com/workbench/?pid=37362458338538649&%3Bmi=spec%3Afc2aabd3-3ce5-45de-a846-2a416494b7df%2Cservice%3AMESHING%2Cstrategy%3A2&%3Bsh=1)** > > Log in to your SimScale account. SimScale makes high-fidelity engineering simulation technically and economically accessible. At any scale. In the cloud. Thanks so much. ---
**Author:** ![HamzaBaig](https://www.simscale.com/forum/user_avatar/www.simscale.com/hamzabaig/32/61949_2.png) [@HamzaBaig](https://www.simscale.com/forum/u/HamzaBaig)\ **Post date:** [September 24, 2019, 11:31am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/4 "2019-09-24T11:31:03Z")
@andrea_perez, Wait, i am checking your project. ---
**Author:** ![HamzaBaig](https://www.simscale.com/forum/user_avatar/www.simscale.com/hamzabaig/32/61949_2.png) [@HamzaBaig](https://www.simscale.com/forum/u/HamzaBaig)\ **Post date:** [September 24, 2019, 12:44pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/5 "2019-09-24T12:44:50Z")
@andrea_perez, Check the simulation named as (Incompressible Hamza) on the following link. The mesh is generated as described in the validation case. Regards ---
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 24, 2019, 1:13pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/6 "2019-09-24T13:13:28Z")
Hi! This mesh is not appropiated for this kind of problems. Boundary layers have to be create in order to assess the y+. Thanks anyway. I will try by myself. ---
**Author:** ![HamzaBaig](https://www.simscale.com/forum/user_avatar/www.simscale.com/hamzabaig/32/61949_2.png) [@HamzaBaig](https://www.simscale.com/forum/u/HamzaBaig)\ **Post date:** [September 24, 2019, 1:16pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/7 "2019-09-24T13:16:18Z")
Have a look at this mesh clip. it is showing the B.L ![bl](https://www.simscale.com/forum/uploads/default/original/3X/3/7/37cd5697b02d4b09a360141744bf23ace61f35e8.png) ---
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 24, 2019, 1:27pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/8 "2019-09-24T13:27:41Z")
Okay. It is a visual mistake. I have to use a cutting plane to see the mesh. I will check my model by this way. Thanks ๐Ÿ™‚ ---
**Author:** ![HamzaBaig](https://www.simscale.com/forum/user_avatar/www.simscale.com/hamzabaig/32/61949_2.png) [@HamzaBaig](https://www.simscale.com/forum/u/HamzaBaig)\ **Post date:** [September 24, 2019, 1:29pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/9 "2019-09-24T13:29:56Z")
You have to generate a mesh clip to visualize the mesh inside the domain. ---
**Author:** ![jousefm](https://www.simscale.com/forum/user_avatar/www.simscale.com/jousefm/32/34908_2.png) [@jousefm](https://www.simscale.com/forum/u/jousefm)\ **Post date:** [September 24, 2019, 3:56pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/10 "2019-09-24T15:56:17Z")
Hi @andrea_perez! Instead of relying on the visual mesh you can also add a result control item to show the y+ value in the post-processor ๐Ÿ™‚ Let us know how things go! Jousef ---
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 25, 2019, 8:52am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/11 "2019-09-25T08:52:12Z")
Hi! I have a problem. When I am making different grids in the several simulation within the same public project, the mesh changes in all simulations, not only in the simulation i want to check, so i am loosing all my tests i am doing. Why is it happening to me ? Thanks ---
**Author:** ![HamzaBaig](https://www.simscale.com/forum/user_avatar/www.simscale.com/hamzabaig/32/61949_2.png) [@HamzaBaig](https://www.simscale.com/forum/u/HamzaBaig)\ **Post date:** [September 25, 2019, 9:53am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/12 "2019-09-25T09:53:34Z")
Can you share the project link? So that we can check. ---
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 25, 2019, 10:01am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/13 "2019-09-25T10:01:45Z")
I have already found the problem. I think that, when I copy a simulation, i have to create a new mesh, otherwise , the grid will be the same for all simulatios since it is not independient. This is the reason why, when i do tests, the mesh change in all simulations. Let me know if this is correct. Thanks ---
**Author:** ![jousefm](https://www.simscale.com/forum/user_avatar/www.simscale.com/jousefm/32/34908_2.png) [@jousefm](https://www.simscale.com/forum/u/jousefm)\ **Post date:** [September 25, 2019, 10:12am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/14 "2019-09-25T10:12:36Z")
Hi Andrea! All the meshes that have been created in the copied project are maintained and not changed and will be fully available in the copy. How do you come to the conclusion that there is a change in the mesh? Maybe I miss your point here ๐Ÿ™‚ Cheers! Jousef ---
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 25, 2019, 11:25am UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/16 "2019-09-25T11:25:07Z")
Hi! I cant explain very well but it is okay! I have another problem regarding with y+. In the following validation case of fluid dynamics, you can see several values of yplus: > **[Turbulent Flow Through Pipe | Validation Case | SimScale](https://www.simscale.com/docs/validation-cases/turbulent-pipe-flow/)** > > This SimScale validation case assesses incompressible steady-state turbulent models applied to water flow through a straight pipe. But, when i try to obtain those values in the same exemple, i am not able to do it. In the next pictures, you can see my results. I think i donโ€™t know very well to check the Yplus in SimScale. Could you help me with this? [simscale\_kEpsilon\_wallFunction|690x338](https://www.simscale.com/forum/uploads/short-url/7j3JknUyIt3U4hLKlUOUx1Ek7gP.png) ![simscale_KomegaFullResolution](https://www.simscale.com/forum/uploads/default/original/3X/e/1/e104754c6a8b49faf7b518d1945882797a6f9b1a.png) ![simscale_KomegaWallFunction](https://www.simscale.com/forum/uploads/default/original/3X/b/e/be070f8db627c9e2826cf54cc6e2a4216e100957.png) Thanks!!! ---
**Author:** ![jousefm](https://www.simscale.com/forum/user_avatar/www.simscale.com/jousefm/32/34908_2.png) [@jousefm](https://www.simscale.com/forum/u/jousefm)\ **Post date:** [September 25, 2019, 12:09pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/17 "2019-09-25T12:09:31Z")
Hey Andrea! Some posts that might be helpful to you: - **[Y+ (yplus) - Generate Wall Spacing for CFD](https://www.simscale.com/forum/t/y-yplus-generate-wall-spacing-for-cfd/82451)** from our PowerUser @Get_Barried - **[What is y+ (yplus)?](https://www.simscale.com/forum/t/what-is-y-yplus/82394)** - A Short Introduction * * * Best, Jousef ---
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 25, 2019, 12:58pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/18 "2019-09-25T12:58:26Z")
how can i check the y+ without using Paraview? Just using the postprocessing on the cloud Thanks ---
**Author:** ![HamzaBaig](https://www.simscale.com/forum/user_avatar/www.simscale.com/hamzabaig/32/61949_2.png) [@HamzaBaig](https://www.simscale.com/forum/u/HamzaBaig)\ **Post date:** [September 25, 2019, 1:29pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/19 "2019-09-25T13:29:30Z")
First you have to create a field calculation of y plus in the result control. As shown below. ![y%20plus](https://www.simscale.com/forum/uploads/default/original/3X/e/a/ea70fd52c6ead6517cd7925ca8b59c8614018935.png) Then you can see the y plus result in the Post processor. As shown below. ![y](https://www.simscale.com/forum/uploads/default/original/3X/8/c/8cc9c027574a8150590ef575f910daa4a16b5fb4.png) Regards ---
**Author:** ![andrea\_perez](https://www.simscale.com/forum/letter_avatar/andrea_perez/32/6_22734026db12803ebb3e059622ac3534.png) [@andrea\_perez](https://www.simscale.com/forum/u/andrea_perez)\ **Post date:** [September 25, 2019, 1:39pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/20 "2019-09-25T13:39:12Z")
I have already done that as you can see on my pictures in previous posts. So, why the y+ obtained in those pictures are different compared with the validation case if the model used is the same? thanks! ---
**Author:** ![HamzaBaig](https://www.simscale.com/forum/user_avatar/www.simscale.com/hamzabaig/32/61949_2.png) [@HamzaBaig](https://www.simscale.com/forum/u/HamzaBaig)\ **Post date:** [September 25, 2019, 2:07pm UTC](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365/21 "2019-09-25T14:07:23Z")
Your model is not the same as in the validation case, your model have different dimensions, So there should be different mesh and B.L settings to obtain the same result. [Next page](https://www.simscale.com/forum/t/meshing-turbulent-pipe-flow/86365.md?page=2)