# Convergence not Reaching!

**URL:** <https://www.simscale.com/forum/t/convergence-not-reaching/81935>\
**Category:** Project Support\
**Created:** [March 17, 2018, 8:03pm UTC](https://www.simscale.com/forum/t/convergence-not-reaching/81935 "2018-03-17T20:03:46Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**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:** [March 17, 2018, 9:49pm UTC](https://www.simscale.com/forum/t/convergence-not-reaching/81935/2 "2018-03-17T21:49:28Z")

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Hi @simscale7yahoo!

The simulation you are referring to has converged. Some remarks from my side:

- Why do you choose the bottom wall to be no-slip?

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You can use two custom boundary conditions with one defining the BC of the propeller and the other one the bounding boxes. An example can be found here: **[Propeller AMI](https://www.simscale.com/projects/gholami/propeller/)**.

* * *

- The velocity you put in is not going through the propeller as it should

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It should be the negative x-direction and you have defined the geometry to be stationary so far. I do not think that using a moving wall velocity of the bounding box is a good substitute for the AMI/MRF approach. So you should consider working with that. That’s why you have probably opened up **[another post](https://www.simscale.com/forum/t/mesh-error-rotating-zone/81934)**.

Cheers,

Jousef

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