I have set a low resolution smoke simulation using “Pyro Solver (Sparse)”. The desired shape of the smoke is obtained with “Voxel Size = 0.05” (relatively a low resolution).
When I increase or decrease the “Voxel Size” I get something unwanted.
When I increase the“Voxel Size”, the smoke expands more. When I decrease it the smoke contracts.

As you can see in the attached picture, the blocs and rectangles.


So I cached the simulation at that resolution (“Voxel Size = 0.05”), then I increased the resolution of the simulation, following this tutorial.
Sparse Pyro Upres, the easy way. [vimeo.com]

I increased the resolution of the simulation by setting the “Voxel Size = 0.02”.

I thought that after doing an “Upres” for the simulation this would get rid of those artifacts.
Well, the overall resolution of the simulation is increased however I still have some of the artifacts in the final render.
As you can see in the attached screenshot.

So how to get rid of those artifacts and obtain a smooth and clean smoke shape?

Thanks for your help.

That's the result of shredding and pushing your density shader too high.

Enivob
That's the result of shredding and pushing your density shader too high.

Thanks for pointing this out.

Also if you don't add any turbulence in your upres, you're just upscaling the sim, making any lowres issue more visible.