well with 2nd BC

Hi all!
I’m designing a 3D modell with several slices and want to add a multi-layered well by a 2nd kind intergral BC at an area with the size of the borehole.
The pumping rate Q has to have a given constant value. How do I hacve to compute the flux rate q when Q is independent of the thickness of the aquifer? (Q=2q*l*B)
As the online help says, the water exchange will take place to both sides of the defined area. Does that mean, that the well will be injecting and pumping? Do I have to apply an In or Out transfer rate for the cells inside the defined area (well)?

Thanks for help!
Stefanie

Hello Stefanie,

why do you want to use a 2nd kind (Neumann) bc for the well instead of 4th kind? Is it a large scale model just for the immediate vicinity of the well?

As for "both sides": the bc flux value is applied on both sides so the well will be pumping the defined amount of water both from inside and from outside the borehole boundary (same sign, no injection), at least if the inside of the well is also part of the model domain (no mesh hole).

Jochen

hi!
by using the constrains of 2nd type boundary (Max=0) you design the boundary as outflow only,so you solve the "injecting" problem.
transfer in/out will only goes with 3rd. type boundary. so that won't help you.
consider changing the Kz of the well cell to infinite number so once water will enter the "well cell" they will be run quickly upward.
good luck!

Elad Dafny