Constant Flux Boundary & Convergence Problem

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ES_92
Posts: 19
Joined: Sun Dec 06, 2020 11:22 am
Location: Italy

Constant Flux Boundary & Convergence Problem

Post by ES_92 » Mon Mar 15, 2021 10:57 am

Dear all,
I have been working with a soil column model in Hydrus 2D to simulate the wetting front behavior of a porous pipe in sandy soil. The pipe (circle) has constant flux boundary of -4.14 cm/hours (picture attached). The initial soil water content was assumed equal to the field capacity. Simulation period is for 3 hours and the time criteria values are chosen as default values. But when I run the model it says "Numerical solution has been stopped since it has not converged in 10 consecutive time steps !"
But when I try with positive value, the model is running. Is my approach wrong? I have got a lot of help from this forum while setting up the model but I am not able to proceed in this step. Your comments will be helpful to solve the problem. I have also attached the model. Waiting eagerly for the response.
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BC.PNG
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Jirka
Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Constant Flux Boundary & Convergence Problem

Post by Jirka » Mon Mar 15, 2021 6:17 pm

As is stated in the help and manual: “A constant flux boundary condition (positive for inflow into and negative for outflow”. A positive value thus represents irrigation (which is what you want to do), while a negative value would represent the removal of water from the soil (which clearly cannot happen at this rate from sand). J.

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