Hi! Sorry for ignorance of the language, I will try to learn;) There is a channel with water! How to include the roughness of concrete? 

Hello,

Edit the Concrete material and give it a wall roughness :)

Let me know if you can't find it.

Hi @svetashov,

To embellish on what Jon said a bit, assign the material as default concrete, hit edit, and then switch the material from Default database to Local or My Materials. Then assign the wall roughness based on a book value. 

Looking quickly online, I see wall roughness values of 0.3 - 3 mm. I found this page on roughness values. 

Thanks,

Thank you! If you choose concrete (scenario> material> concrete), is the roughness set automatically? 

@svetashov,

The default is 0. You can see that above.