PHYS 220 — Lab #9
This lab is the final section of a two-part sequence that will
address certain topics
in electromagnetism. In this first part you will numerically solve
Laplace's equation and learn a few techniques for visualizing the
solution.
The assignment is
due at the beginning of lecture on
Monday, 20 April.
Your solutions should include code listings
and plots of the potential, the electric field and the level of
convergence in your solution at exit.
- Select a conductor configuration from your text shown in either
Fig. 5.4, Fig. 5.6 or given by Exercise 5.6.
- For your selection, use the Jacobi relaxation method to solve
Laplace's equation for your conductor configuration. It will help
to code a few modules to tackle the problem:
- conductor configuration initialization (boundary conditions)
- solution mesh initial guess ("initial" conditions)
- single Jacobi step
- Jacobi relaxation stepper
- electric field calculation
- plotting/visualization
- You calculate your electric field after you solve for
the potential. The electric field is
simply E = -∇V. For example, in the x-direction this is
Ex = - ∂V/∂x ≈ -(V(i+1,j) - V(i-1,j))/2Δx.
Note that using this
formulation, you must be careful not to use cells that are outside
your boundary conditions. You can also use
the gradient function in MATLAB to
calculate this.
- A suggestion is to explore my Jacobi method codes on
the course outline and adapt them
for your own purposes. Too, you may want to begin with a relatively
coarse mesh for your first attempts, then make your mesh finer for
your final submission.