Interesting behaviour of residuals

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Sidemountyucatan
Posts: 114
Joined: Wed Apr 17, 2019 2:08 pm

Interesting behaviour of residuals

Post by Sidemountyucatan »

Residuals.png
Residuals.png (67.9 KiB) Viewed 1914 times
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.23074 (Git)
Build type: Release
Branch: master
Hash: 74b866ed3022fd1452c534dae31a721bcc668f2f
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: German/Switzerland (de_CH)

Hi,

I have a interesting behaviour of the residuals when simulating my case. (File attached). In the first run I defined the velocity at the nozzle inlets and the pressure at the outlet. The residuals of al parameters did a smooth decend down to 10-4 / 10-5.

In the actual case I just switched the boundary conditions; means pressure at the nozzle inlets and velocity at the outlet. In this particular case the residuals did decend first but then climb again to 10-2 and stayed stable this size. (residuals attached)

Nothing else was changed. (geometry, grid, initial conditions etc.)

Can somebody tell me why this happens ?

Thx
Attachments
Flow in cleaning tank_modified boundaries.FCStd
(279.9 KiB) Downloaded 58 times
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Kunda1
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Joined: Thu Jan 05, 2017 9:03 pm

Re: Interesting behaviour of residuals

Post by Kunda1 »

bump
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