Reason for difference in simulation time for two soils

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mGohar
Posts: 36
Joined: Wed Jul 15, 2015 11:16 pm
Location: USA

Reason for difference in simulation time for two soils

Post by mGohar » Mon Nov 21, 2016 10:18 am

Hi,

I'm just curious why there is a huge difference in simulation time between two soils I'm concerning. Here I'm considering just water flow in a 3D domain with drip irrigation and about 360,000 3D-Elements. For the first soil it runs really fast but in the second one it takes more than 15 times longer. The hydraulic parameters are as follow:

Th_r Th_s alpha [cm-1] n Ks [cm.hr-1]
Soil_1 0.02 0.874 0.0623 1.3022 30.99
Soil_2 0.01 0.549 0.4534 1.2629 39.25


and I also like to know is there something I can do resolve this issue?

Thanks,
Mohammad

Jirka
Posts: 4805
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Reason for difference in simulation time for two soils

Post by Jirka » Mon Nov 21, 2016 4:34 pm

These two soils have very different soil hydraulic parameters (mainly due to different alphas). As a result the nonlinearity of the problem (note that the Richards equation is a nonlinear equation) is very different as well. The speed of the solution depends on this nonlinearity. J.

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