  The practice-based learning methodologies offer to undergraduate professors
different ways to illustrate certain general physic principles. Traditional
experimental workbenches have been extensively used during decades for academic
lessons in order to complete theoretical dissertations or lectures, aiming at
assuring an adequate understanding. The high cost of materials and laboratory
equipment, the excessive preparation time, and the difficulty for carrying out
offsite-campus replications by students, are disadvantages that can discourage
of trying new kinds of experimental tasks. This paper gives insight of
simulated experiment possibilities through an open-source-based computational
suite in teaching fluid mechanics. Physics underlying diffusion of a light
specie in a heavier atom matrix, as function of time and position, were
explained to students as an example to teach them the Fick's Second Law
expression. We present a docent step-by-step programme, scheduled in three
sessions. The expected solution is firstly explained and then compared both to
a real case, by published results, and to the virtual-classroom experiment, by
resolving a differential equation with numerical schemes. Students were able to
make their own hypothesis, change input parameters, and contrasting their
initial assumptions.
