User Guide

This guide will help a user understand existing examples, and design new ones.

The first step of writing an EchemFEM script is to import the EchemSolver class:

from echemfem import EchemSolver

or for a transient simulation, the TransientEchemSolver class:

from echemfem import TransientEchemSolver

These are abstract classes, which we will use as the base class for a specific model. To create a customized solver, the user should set the following inputs:

Here is a barebone example of how a user might define their own solver. Several concrete examples can be found in echemfem/examples.

class MySolver(EchemSolver): # or TransientEchemSolver

    def __init__(self):
        # Here define all custom parameters that may require attributes

        super().__init__(...) # with appropriate arguments

    def set_boundary_markers(self):
        self.boundary_markers = ...

    # and some other methods that need to be defined

Then, to run the simulation, create the object and run the solve method.

solver = MySolver()
solver.solve()

For transient cases, a temporal grid defined as a list or numpy.ndarray must be provided. For example,

import numpy as np
times = np.linspace(0, 11, 1)  # 10 timesteps of size 0.1
solver.solve(times)

To generate non-trivial velocity fields, some fluid flow solvers are available:

Fluid Flow Solvers