Dear Sir:
I want to coupling two Richards equation exactly on the same Geometry, to represent two different subsurface flow with different velocity, and define a function as a source sink term depend on the difference of pressure head to calculate the exchange of water. I can let two Richards equation calculated simultaneously, but I can not couple them and calculate the exchange, can you tell me how to couple 2 Richards equations and calculate the water exchange between them?
another question is, it is seems that ComSol is not very stable when solving Richards equation, especially when initial saturation and pressure head is very low, I can see the obvious overshot which is caused by numerical problem, can you tell me how to solve this problem?
I want to coupling two Richards equation exactly on the same Geometry, to represent two different subsurface flow with different velocity, and define a function as a source sink term depend on the difference of pressure head to calculate the exchange of water. I can let two Richards equation calculated simultaneously, but I can not couple them and calculate the exchange, can you tell me how to couple 2 Richards equations and calculate the water exchange between them?
another question is, it is seems that ComSol is not very stable when solving Richards equation, especially when initial saturation and pressure head is very low, I can see the obvious overshot which is caused by numerical problem, can you tell me how to solve this problem?