how to modify a solver to add a disturbance
 

how to modify a solver to add a disturbance? In a solver I am going to add a disturbance in a solver while the values of some fields is constant.However the constant values is not a simple one ,i can not solve it just in the solver code .
How can I handle it?Thanks a lot.

If you're talking about adding a disturbance via a boundary, for example: an abrupt change in the value of a boundary condition at a specified time, then I'd suggest you look into using groovyBC (http://openfoamwiki.net/index.php/Contrib_groovyBC) which makes this type of thing fairly easy (or you could hard code it too).

I am sorry i did not explain it clearly.I mean some classes of values do not change while time varies,however,the constant values can be very complex,in ditails,the values in different earas vary.the disturbance means some other classes,whose values depend on both the constant and theirselves.for example,the B (magetic),in the magneticFoam slover
,is constant.