SimScale CAE Forum

Car diffuser

The simulations are not converging even with the default mesh set up
renaissance | SimScale Workbench

can someone help me i dont know what is going on ?

Hi,

The problem is with mesh quality (see the steps to evaluate mesh quality here).

Inspecting the quality metrics, the problem originates from 20 boundary layers being added, especially close to these small faces.

Cheers

hi i was try to control the y + value

Dear Jkaka:

  1. Why are you using manual relaxation types?
  2. Start with a y+ between 30 and 150 (wall-function) and verify the simulation runs well. You can even use it as initialization for your definitive case (I am not sure if SimScale has that capability already).

Hi sir the y+ should be less than 1 for an accurate result specially when you use incompressible flow right ?

This is not necessarily true. You can use wall functions, which work very well in most cases. . Check out this post: https://www.simscale.com/forum/t/what-is-y-yplus/82394