Q:

Simulate / plot electrostatic field

I have something like this: 

For given voltage (9 V red wire, 0 V blue wire) I want to simulate electrostatic field.  
I already know, for example that in the point (10.5;0) there are 10 V and etc. 
I want to simulate and plot electrostatic field for future comparison and for my report. 
Is there any software for doing that?  I like to work with Maple, so if there is any toolboxes, I would be glad to hear about them. 
For slightly different position plot looks awful now: 

A:

As I said earlier in my comment, Comsol is pretty useful for these sort of things.  I took your problem, and this is the plot that I got.  I hope it's useful. 