The concept of a breadcrumb or breadcrumb trail is derived from Hansel and Gretel fairytale by the Brothers Grimm. Hansel leaves a trail of breadcrumbs in the woods to find his way out.
In our context, the woods is of course an area of applied thermodynamics in which students are struggling to locate and navigate, and the breadcrumb trail is a progressive presentation designed to facilitate their phenomenological understanding in terms of both quality and quantity.
They are primarily intended for teachers, to whom they can serve as a guide for preparing their lessons, but also directly for students sufficiently independent to work by themselves.
The breadcrumbs begin with a knowledge map in wich the main topics are addressed, and continue by a chain of explanations, from simple to more advanced, with illustration by concrete examples.
Although partly redundant with other portal pages, including thematic pages, they are complementary because their ambition is to approach as completely as possible one aspect of the subject matter, by browsing through the main educational milestones allowing its understanding, while representing a reasonable amount of work in practice.
For example, the breadcrumb trail on single phase heat exchangers is an example of simple heat exchanger design, from its enthalpy balance to its geometric sizing and off-design behaviour, but limited only to notions necessary to understand this example.
Even if it was not originally designed on the model of a breadcrumb page, the page on Basic concepts and qualitative approach of the thermodynamic laws is quite similar. Therefore it is also published at the beginning of this section.