## Educational method presentation

### Overview

Over the past thirty-five years, we have developed a new pedagogy of thermodynamics applied to the thermodynamic conversion of energy, now used in more than one hundred and twenty higher education institutions, both in bachelor's and master's degrees (engineering schools, universities) as well as in professional training.

The process of developing this new pedagogy was long because we had to invent and develop many digital resources and test them with various categories of learners.

This work has only been possible thanks to the support of **many organizations and individuals** to whom we extend our sincere thanks, and in particular the **UNIT Foundation**, which has played a decisive role.

From year to year we have gathered in this portal various documents relating to our new pedagogical approach. Even if they share the same common base, sometimes their content varies slightly depending on when they were written. We apologize for that.

We present in this page all the elements that underlie the pedagogies that we recommend.

Regarding the difficulties resulting of the classical approach in thermodynamics, we were led to introduce a new pedagogy.

This completely new approach is developed hereunder. Its main points are described in our communication paper for the TICE 2006 symposium (in French only), (which took place in Toulouse from 21th to 23th of October, 2006).

### Presentation of our pedagogical redesign

Our pedagogical redesign revolves around the following points:

A pedagogical redesign with 3 complementary dimensions

The general context of the engineering training

the general context of engineering training

the difficulties encountered in teaching applied thermodynamics

the interest of using the Thermoptim simulator to overcome a first pedagogical difficulty

a second pedagogical difficulty: the teaching of technological reality

the pedagogical interest of directed explorations of models and Diapason sessions

a step-by-step approach in three stages

the detailed follow-up of the students to be set up

the advantages and disadvantages of model building and guided model exploration

complementarities between disciplinary approach and system functional analysis

Three modes depending on the scientific level of the learners

written materials

### A pedagogical redesign with 3 complementary dimensions

Today, it is very common to refer to a triangle when thinking to pedagogy. This particular educational triangle would have as vertices : the student, the teacher and the knowledge.

This analysis highlights three main classes of pedagogies :

that of acquisitions is interested in what the student learns and understands

that of the contents in the way the teacher defines what he teaches

that of relationships is centered on the teacher-student couple

One of the main interests of this triangulation is to remember that there can be no question of restricting a pedagogical approach to only one of these dimensions, as some have sometimes been tempted to do, explicitly or implicitly.

Our pedagogical redesign concerns precisely these three dimensions:

in terms of the pedagogy of acquisitions, our work is in line with the recommendations made by the theoreticians of cognitive sciences and constructivism (see

**references**). We essentially sought to reduce the cognitive load of learners, in particular by relieving them of most of the computational difficulties they faced.as we show below, our approach to content pedagogy corresponds to a radical paradigm shift: instead of resorting to a very axiomatic presentation of the discipline, we propose to start with a qualitative and systemic approach to assembling elementary components, which can be described as functional, and it is only when students have acquired a sufficient culture of the field that the equations a little complex can be introduced if necessary. By using a simulator, we also eliminate the need to teach students the details of the calculation of fluid properties, which is a significant part of classical education. These developments lead to a profound change in the content to be taught, which we propose to articulate according to a model called

**RTM(E)**. To limit the cognitive load imposed on them, the content taught varies according to the scientific level of the learners.Finally, by using our approach, on the one hand learners traumatized by the classic teachings of the discipline are reassured when they realize that it can be put into practice without difficulty, and on the other hand a much more personalized follow-up of the students can be put in place. In general, learners are confronted with alternating online work, which can be done alone or in groups, and face-to-face group sessions. During the time slots dedicated to online work, one-on-one tutoring can easily be set up if desired.

### General context

The context of engineering education has changed significantly in recent years. Even if their **scientific and technical knowledge** and their ability to mobilize them to solve concrete problems are among the specificities that continue to distinguish them most from other senior managers, they must increasingly, like them, be concerned with the **non-technical dimensions** of their work, i.e. personnel management, project economics, product marketing, environmental impact of technologies... Under these conditions, the time they have to invest in the technique and their motivation to do so are now smaller than before. In addition, the hourly volume devoted to technical subjects in engineering training programmes is also gradually decreasing, with tutorials and projects often being the first to be sacrificed.

This evolution of the specifications of the training forces us to renew the pedagogies that we implement, but, fortunately, we also have new assets because of the existence of virtual environments.

Although energy can be considered an ancient science (its foundations were established more than a century ago), **it remains a field in very strong evolution** due to both advances in the field of materials or control command, physical and geopolitical constraints on resources, and changes in regulations, which leads to the development of increasingly environmentally friendly devices.

Considerable technological changes are still expected in the coming decades. **They will call on strong skills in applied thermodynamics**, in particular for the development of new integrated cycles with high efficiency and low environmental impact.

Our goal is to train our students in the best possible way so that they can meet these challenges.

### Difficulties encountered in teaching applied thermodynamics

It is well known that thermodynamics is a difficult subject to teach. The problem has been identified for a long time, and many efforts have been made to remedy it, but until recently there was still a lack of solutions, despite the efforts made by teachers and changes in curricula.

The theory/application link, essential for the understanding of any discipline, is much less simple and intuitive in thermodynamics than it is in other fields of physics. In the classical approach to teaching experimental sciences, such as electricity or mechanics, theory and applications to simple achievements are presented at about the same time to students, with if possible some practical work. The relevance of simple models (U = R I, balance of forces) is then easily verified and the link between theory and technology seems immediate; this is how we speak of the "laws" of elementary physics, while they are indeed directly intelligible models that can explain the operation of many very useful technologies known to all (electric lamp, heating resistance, simple machines such as the winch, the hoist, the inclined plane, the pendulum ...).

For energy systems, it is unfortunately **almost always impossible to find models that are both simple and accurate**. Barely caricaturing, one could say that classical approaches to the discipline face a dilemma, the models to which they lead are either unrealistic or incalculable.

In these approaches, given the difficulties in accurately calculating the properties of thermodynamic fluids, one is generally led either to make assumptions that are a little too simplifying, or to adopt methods that are tedious to put into practice: this is how, for example, in almost all undergraduate and graduate education in the world, internal combustion engines are analyzed with the assumption that the technical fluid is air, itself supposed to behave like a perfect gas. As for the calculations of refrigeration or steam cycles, they are made using either numerical tables requiring boring interpolations or relatively imprecise paper charts.

This results in **two pitfalls that have the effect of demotivating students**:

the calculation hypotheses being too simplistic, they do not understand the practical interest of the models they develop, which are very far from reality;

the precise calculations of the cycles being tedious, they are put off by the discipline.

If classical approaches have such limitations, it is in our opinion because they date from a time when the engineer had at his disposal only his calculation rule and his table of logarithms, and that they have not been questioned for several decades...

### Use of the Thermoptim simulator to overcome a first pedagogic difficulty

It is possible to overcome the difficulties encountered by conventional approaches if we note that thermodynamics is much simpler qualitatively than quantitatively, and if we renew the pedagogy by having a **wide use of simulation software** to perform calculations.

The use of the Thermoptim software package allows a student to learn about the study of energy systems by exploring or assembling models of the main energy conversion technologies on their own. Since these are presented as assemblies of components crossed by thermodynamic fluids that undergo various transformations, we greatly simplify things if we **adopt a double approach**, starting by separating the overall representation of the system, generally quite simple, from the study of its various components considered individually.

The overall representation is very useful from a qualitative point of view: it can be done visually and allows a clear understanding of the role played by each component in the complete system. On a didactic level, it is essential to properly assimilate the design principles of these technologies. Once one has in mind the functional structure of an engine or refrigeration unit, the study of the behavior of one of its components is facilitated because one understands how it fits into the whole and what is its contribution to overall operation.

If one has a **suitable graphical environment** such as Thermoptim's schematic editor, the internal structure of the system can be described without any difficulty. We thus obtain a very telling qualitative representation, which then only remains to quantify by thermodynamically parameterizing the different components and then calculating them. This qualitative representation also has the particularity of being to a very large extent independent of the assumptions used for the calculation of the various components: it is an invariant of the system.

**Refrigeration machine in Thermoptim**

This distinction between components and systems plays a fundamental role in the pedagogy we advocate. As much as the number of thermodynamic components most commonly used is relatively small, the systems that can be imagined by assembling them are numerous and varied: there is at this level a field of investigation still considerable for the decades to come.

With regard to the components (compressors, expansion devices, with or without work, exchangers, combustion chambers, etc.), students must understand on the one hand the transformations undergone by the fluids that pass through them and on the other hand the corresponding reference evolutions. They are **the ones who make the link between the technologies implemented and the fundamental assumptions adopted for their modeling** (for example, an exchanger or a combustion chamber is in first approximation isobaric, a compressor or a turbine is generally adiabatic ...).

As for **the systems**, Thermoptim makes it possible to simulate a large number of them, the simplest such as the refrigerator presented above corresponding to one of the basic examples of the discipline, to the most complex involving dozens or even hundreds of components.

**The Thermoptim structure**

The main pedagogic innovations brought by Thermoptim are the following:

First, with

**tedious calculations eliminated**and most quantitative aspects taken care of by the computer, students can focus more on acquiring the discipline's thought patterns.Thermoptim is based on the distinction of a number of elementary concepts, called primitive types, whose structure presented above helps students to fully understand inter-relationships.

using the software package, beginners acquire the vocabulary and basic concepts that are encapsulated in the screens presented and whose design has been done with care ensuring that their content is as simple as possible. Once this vocabulary is learned, cooperative learning with peers and teachers is strengthened.

the

**synoptic diagram editor**Thermoptim is not only a very good tutorial: its features also make it a

**powerful professional simulator**used by manufacturers such as EDF, CEA or Framatomeit places students' thinking at a higher conceptual and methodological level, with purely computational aspects being outsourced to the computer. There is not only a reduction in cognitive load, but also a

**significant increase in problem-solving ability**;Finally,

**Thermoptim makes students truly operational**, which is a major factor in their motivation, and therefore their attention.

If we have on our computer an
**adequate graphic environment** as the Thermoptim diagram editor, the internal structure of a system may be shown without any difficulty. Thus, we get a
**qualitative representation very easy to understand**. This representation is then to be quantified firstly by an adequate parametrization of the thermodynamic properties of the various components and secondly by calculating them. Besides, this qualitative representation is usually not dependent on the hypotheses assumed for the calculation of the various components. This representation is
**an invariant of the system**.

### Second pedagogical difficulty: teaching technological reality

In order to circumvent the difficulties traditionally faced in teaching this discipline, the knowledge to be taught has been profoundly restructured in accordance with a model called
**
RTM(E)**in which the knowledge to be transmitted is grouped into four broad interrelated categories, called **Reality**, **Theory**, **Methods** (and **Examples**).

The presentation of methods and examples is now based on the use of the simulator, which avoids drowning students in boring equations and calculations.

Since the question of calculations is largely solved thanks to the use of software tools, the presentation to students of what we call the **technological reality** has become in our opinion the main residual difficulty: more than 50% of the time spent in class is devoted to the description of the machines, their operating principles and the technological constraints encountered.

This difficulty is reinforced in the classic face-to-face method, which is tiring for both teachers and students, especially if the class sessions are grouped over several consecutive hours.

This is why, in addition to Thermoptim, well suited to teach working methods and examples, but not for technological reality or theory, we have developed from 2004 some e-learning modules provided with a soundtrack called **Diapason** (in French DIAporama Pédagogiques Animés et SONorisés). These modules gather in a concise way all the informations the students need to learn and make them available to them at any time.

Starting in 2015, we have also developed guided explorations of pre-built models with Thermoptim, through which learners can learn how to use the software package to model systems of increasing complexity. We present them a little further down this page.

If we have on our computer an
**adequate graphic environment** as the Thermoptim diagram editor, the internal structure of a system may be shown without any difficulty. Thus, we get a
**qualitative representation very easy to understand**. This representation is then to be quantified firstly by an adequate parametrization of the thermodynamic properties of the various components and secondly by calculating them. Besides, this qualitative representation is usually not dependent on the hypotheses assumed for the calculation of the various components. This representation is
**an invariant of the system**.

### A second educational difficulty: the teaching of the technological reality

A second educational difficulty is the teaching of the technological reality. In order to get round the difficulties which the teaching of thermodynamics traditionally faces, the knowledge to be taught have been deeply reorganized in compliance with a model called :
**
RTM(E)
** , standing for : Reality Theory Methods (Examples). The presentation of the methods and the examples is now based on the use of a simulator. This avoids students to be overloaded with equations and dull calculations.

Since the question of the calculations is now commonly solved by the use of software tools, the presentation to the students of what we call the
**technological reality** is, in our opinion, the main residual difficulty.

More than half of the course duration is dedicated to the description of machines, their running principles and to the existing technological requirements.

This difficulty is reinforced in the in-class classical method which appears tiring for teachers as well as students, particularly if the course sessions are merged over several consecutive hours.

We had to complement Thermoptim because the software is well adapted to teach the Methods and the Examples, but not at all adapted to learn neither the technological Reality nor the Theory. To overcome these difficulties, we have developed in the year 2004 some e-learning modules provided with a soundtrack called Diapason. These modules gather in a concise way all the informations the students need to learn and make them available to them at any time.

### Diapason sessions

The specificity of the Diapason sessions is to associate a soundtrack with a screen, allowing students to obtain contextual oral explanations on issues relating to both theory and technology and the practical implementation of the simulator.

They are an alternative to videos that is much easier to implement and update.

Their structuring in stages, sessions and paths makes it possible to design rich educational environments. They use as a viewer a royalty-free html 5 and Javascript runtime environment, supported by almost all recent Web browsers, which allows you to synchronize various multimedia resources, such as images, soundtracks, pdf documents, spreadsheets, hypertext links..

Their main interest is their excellent pedagogical effectiveness:

when using these sessions, students are more active than in the classroom, in the sense that they regulate their own listening rhythm, but above all they choose themselves the times when they study, and are therefore available when they do; they learn better, especially since they have every opportunity to go back or complete the information presented to them by using written documents;

Since soundtracks have an average length of less than a minute, their attention can be sustained when studying one stage, and they only move on to the next after a rest period;

when they work, students have all the pedagogical resources they need; in case of doubt or if they have been absent, they can refer without any difficulty to the oral explanations of the teacher.

**Videos**

Since 2016, the French version of these Diapason modules have been supplemented by **videos** (about sixty for applied thermodynamics and about sixty for global energy problems).

### Three-step phased approach

We believe that learning is an iterative process that lends itself well to a **progressive pedagogy**, ranging from simple (but still realistic, it's fundamental) to complicated. For both cognitive and psychological reasons, it is better, and this is particularly true of applied thermodynamics, to start by showing students how the knowledge presented to them can concretely be applied, limiting conceptual difficulties as much as possible. Remember that they must above all become familiar with a new reality, which they hardly know, and that this learning already translates into a high cognitive load.

At first, it seems better to show them that there are environments like Thermoptim with which
**they may study thermodynamics easily** and get very accurate results without writing a single equation. Once their initial reluctance is overcome and they have assimilated the vocabulary and basic concepts, it becomes possible to take a new step and introduce equations. The experience accumulated over the past twenty years confirms that, once they have realized that there are now very efficient methods to move to application, learners initially very reluctant with regard to the theory often ask for deepening: as soon as the psychological blockages put in place by presentations of the discipline too axiomatic and very little applicable have fallen, students become much more receptive to equations, probably because they are no longer afraid of being unable to put them into practice. Many people want to know more and understand how the calculations are done.

A little more in-depth discussion (in French) on the pedagogical use of simulators, as well as on the very controversial question of equations that must be presented to students, was presented during a guest paper at the SIMO 2006 Symposium – Information Systems, Modeling, Optimization and Control in Process Engineering: The Virtual in Everyday Reality, on October 11 and 12, 2006 in Toulouse.

Guest paper at the SIMO 2006 Symposium

Based on the feedback from our students, it seemed desirable to graduate the progression in **three main stages**:

the acquisition of concepts and tools, dedicated to thermodynamic reminders, the study of basic cycles, the discovery of the technologies implemented and the learning of Thermoptim

the consolidation of the concepts seen in the first stage, possibly with theoretical additions on

**exergy**, combustion and heat exchangers, the study of variants of basic cycles, combined cycles and cogeneration. This step can be an opportunity to think about how to improve the basic cycles by reducing irreversibilities.deepening and personal application, giving rise to the study of innovative cycles and reflections on technological perspectives, on the occasion of mini-projects carried out alone or in groups.

For instance, you may consult the
**self-training module related to energy powered systems**
. It will show you how these principles may be brought into practice.

### Detailed follow-up of students

Due to the existence of Diapason sessions, students work partly online and partially during mandatory face-to-face sessions, according to a dosage that depends on the context.

It is understood that greater flexibility in the schedule also carries certain risks, including lack of attendance. It is therefore necessary to set up a rigorous follow-up of the students, and do not hesitate to relaunch them regularly by email to remind them to move forward in their work.

At the start of the course, it seems desirable to us to distribute to the students a double-sided sheet specifying the **pedagogical objectives** of the course, which serves in a way as training specifications and contract between them and the teacher. It should distinguish between what must be perfectly memorized, what must be understood and the know-how to be acquired.

The evaluation mechanism that seems to us today the best includes a small oral and a personal work on project, usually carried out in pairs.

The oral makes it possible to ensure in a quarter of an hour that each of the students has memorized a certain number of basic concepts, such as the pace of the elementary cycles, their representation in the usual diagrams, and has understood the foundations of the discipline. The project, which takes place face-to-face with supervision, makes it possible to verify that it has put into practice the knowledge acquired on a concrete case.

### Model construction and guided exploration of models?

A tool like Thermoptim allows one to complete a classical teaching of thermodynamics by a wide variety of educational activities, which can be grouped into two main categories:

those of

**discovery and initiation**, notably by exploration of predefined modelsthose of

**model building**, which concern students seeking to learn how to model energy systems by themselves.

From 1998 to 2016, the main use that was made of this tool in higher education corresponds to the second category. It allows learners to get to the bottom of things and learn to build different thermodynamic cycles by themselves, and thus gives them a very high autonomy, a motivating factor, especially when they are on an internship in a company.

However, it assumes that their first steps in using the software package are the subject of tutorial sessions requiring supervision by teachers who are well versed in the tool, some manipulations requiring a little practice.

For other teaching contexts, the first category can also have many advantages. To reduce the difficulties associated with using the software package, learners do not build the models themselves, but explore and parameterize models already built.

The scenario is presented in a specific Java browser capable of emulating Thermoptim, which offers different activities to learners, such as finding values in the simulator screens, reconfiguring it to perform sensitivity analyses... Contextual explanations are given to them gradually.

**Guided explorations** are defined in an html 5 file, which makes it possible to open and close Thermoptim files corresponding to the models studied, to trace the cycles in the thermodynamic diagrams, and to propose small quizzes to the learners so that they can check their good understanding of the methods covered.

This ensures that they do not waste time on handling errors that are not of pedagogical interest, which is essential if their work can be carried out in the allotted time. The risk of error decreases considerably, and if it occurs, learners simply reset the browser by reloading the files they have.

For example, in the **MOOC Thermodynamic Conversion of Heat** (in French), the simulator is mainly used in the form of about twenty guided explorations of existing models.

### Disciplinary approach and functional system analysis

Classical initial training is aimed at learners accustomed to following disciplinary courses: the division of their teachings into subjects disconnected from each other is quite usual for them and generally does not pose any particular problem for them.

Since middle school, these students have become accustomed to moving from one subject to another by following their school schedule and without questioning its overall logic (Mathematics from 8am to 10am, English then...).

It turns out, however, that this state of mind is generally not shared by learners in vocational training or who have long since left the education system, for whom the only courses that make sense are those that are directly related either to the profession they will practice at the end of their course or to the practical application that interests them. These learners are very reluctant when asked to take courses, especially theoretical ones, if they do not see the immediate interest.

Their concern is to acquire one or more skills, and the link with the job must be clearly explained to them. They may not even be able to get involved in the training until they have been explained the concrete purpose of the program.

For them, the disciplinary approach is not justified at all a priori, quite the contrary, and, if we want to motivate them to invest in these courses that they often consider boring, we must resort to more motivating pedagogies.

Such learners are therefore not at all part of the Cartesian deductive logic, which consists in starting by presenting the reminders of mathematics and physics before unfolding the theory, to end up in practice, the logic that underlies the usual scenario of courses in initial training in higher education.

Even for students in initial training, this mode of presentation is not necessarily the most suitable. Nowadays, learners only engage if they perceive the meaning and interest of the courses offered to them.

**System functional analysis** (SFA) is a method developed by the French Navy at the Naval Training Center of Saint Mandrier (the name was chosen by Mr. F. Colonna, teacher at the CIN).

It is a pedagogical method that relies on the tools of Functional Analysis (basically a method for designing technical or organizational devices), to define a guiding thread allowing students to discover and understand the different elements composing the systems they study, and the links that connect them.

In particular, it makes it possible to identify the best way to introduce scientific prerequisites in a contextual way, thus strengthening students' motivation to learn them.

It is a method that is very well suited for students of low level in mathematics and physics, or for professionals in continuing education who have been active for a long time and have forgotten their basics in these disciplines.

But functional analysis is also of interest to students in initial training in engineering school or university: it gives them a complementary look at the systems they study.

Specifically, in order to enable beginners to understand and study the cycles of three basic energy technologies: steam power plant, gas turbine and refrigerating machine, we advocate choosing a presentation called **CFRP** for **Components, Functions and Reference Processes**.

In the CFRP presentation, we start by describing the architectures of the various technologies and the technological solutions implemented (boilers, turbines, pumps, condensers, turbocompressors, piston, scroll, screw, hermetic compressors, expansion or throttling valve, etc.). We then show that despite their diversity, the components only perform **four main functions**, themselves corresponding to **three reference processes undergone by the fluids** which pass through them.

### Three modes depending on the scientific level of the learners

**Genesis of our pedagogical approach**

In **the early 1990s**, we began teaching a thermal machine course to students at the École des Mines in Paris, having had to replace a colleague who had been immobilized for health reasons at short notice. Like the vast majority of teacher-researchers, we started for about two years by slipping into the mold set up by our colleagues using a pedagogical approach close to theirs, and it was only then that we questioned it, when we found ourselves in a situation of pedagogical failure.

The class was going badly with the students, and given their level, we couldn't blame them. In delving deeper into the question, we came to the conclusion that if one thing was to be questioned, it was essentially traditional pedagogy.

It is well known that thermodynamics is a difficult subject to teach. The problem has been identified for a long time, and many efforts have been made to remedy it, but until recently there was still a lack of solutions, despite the efforts made by teachers and changes in curricula.

First of all, our main pedagogical objective was and still is to make our students able to study innovative energy systems, which involves:

sufficient mastery of the theoretical bases

in-depth knowledge of

**technological aspects**(existing achievements, main constraints)the ability to design and size innovative thermodynamic cycles.

To our surprise, our approach has proved to interest a much wider audience than that of our students at Les Mines, not only at university level, but also for the training of learners who do not have as much scientific background as our students, such as operators of propulsion systems and refrigeration and air conditioning installations of the French Navy or professionals in continuing education.

The result, **after about 2010**, was an **effort to lighten the scientific content of teaching**, with emphasis on understanding physical phenomena rather than studying the equations that describe them and that the latter learners never apply on their own in their professional practice.

In particular, it seemed preferable to us in this context to start the course by **avoiding the notion of entropy** difficult to understand by learners who do not have advanced knowledge of mathematics and physics. This led us to replace the entropic diagram (T,s) with the **enthalpy-pressure (h, ln(P)) chart**.

At the same time, new tools have been developed during the preparation of our two MOOCs Thermodynamic Conversion of Heat, so that learners can work independently, the supervision being necessarily reduced in this context.

These are, on the one hand, **self-assessment activities**, and on the other hand, the **guided explorations of models** mentioned above.

All these developments have led to an evolution of our initial pedagogical approach integrating on the one hand these new tools and on the other hand this concern to lighten as much as possible the scientific prerequisites. We are talking about a **lightweight pedagogical presentation**.

As a result, our pedagogical approach can now be broken down into three complementary modes depending on the scientific level of the learners

Note that the content to be taught differs according to the context, in particular according to the pedagogical preferences of the teachers as well as the **scientific level of the learners** and their learning styles.

The choice between **exploration and model building** also determines pedagogy, as we have seen.

If we distinguish three scientific levels (typically baccalaureate, bachelor and master) and two types of use of Thermoptim, we can consider six main pedagogical modes, but in practice three are enough, especially since nothing prevents from mixing them.

The **first mode**, the **lightweight presentation**, meets the needs of learners with minimal scientific background, and therefore does not involve entropy or exergy. The practical exercises use guided explorations of simple models. This is typically the course offered in our CTC MOOCs (in French) as well as in our **Online course 2022 on Energy Systems**.

The **second mode**, which can be described as **progressive**, is aimed at learners in bachelor's degree or professionals in activity, not particularly motivated by the theoretical aspects while being able to follow them if necessary. It begins with the lightweight presentation that is completed by introducing a cycle improvement approach based on the exergy balances and the comparison with the Carnot cycle in the entropic chart. The practical exercises use guided explorations of models as well as some Diapason sessions.

The **third mode** is intended for students in master or engineering school familiar with theoretical developments. It differs from the previous ones by three points:

First of all, these students are used to a "Cartesian" and disciplinary presentation of their teachings, and nothing prevents us from first introducing them to the whole theory before moving on to applications;

Then, as for them the use of entropy poses no problem, we can very quickly introduce entropic diagrams (T, s) and those of Mollier (h, s) as well as exergy balances ;

Finally, the use of Thermoptim can be done both in the form of exploration and model building.

The approach to improving cycles based on the exergy balances and the comparison with the Carnot cycle should also constitute in the third mode the guiding principle of analysis of the variants of the simple cycles. The practical exercises use either guided explorations, including those using Thermoptim's advanced features, or Diapason sessions where learners build their own models. Most of the **course modules** offered in this portal correspond to this mode.

To varying degrees, each of these modes is based on the elements presented in this page. Historically, it is first the third that has been implemented.

The second edition of the** book Energy Systems** covers topics corresponding to the first two modes.

### By way of synthesis

The pedagogical method we recommend is based on a few major constants:

**reduce the cognitive load of learners**by limiting unnecessary theoretical developments as much as possible, which vary according to the scientific level of the learners**make them operational**thanks to the simulator that allows them to study real problems and not caricatures of reality given too simplifying hypotheses**shift the content of teaching**by reducing the equations and insisting on qualitative explanations of the physical phenomena that take place in the systems studied**sequence the sequence of concepts**presented based on the RTM(E) model and the functional approach.

The training offer with Thermoptim has thus been completed and diversified and reaches a wide audience, nationally and internationally.

### Textbook

A book **Energy Systems: A New Approach to Engineering Thermodynamics** has been published by CRC Press.

The reader is explained how to build appropriate models to bridge the technological reality with the theoretical basis of energy engineering.

This volume is intended for courses in applied thermodynamics, energy systems, energy conversion, thermal engineering to senior undergraduate and graduate-level students in mechanical, energy, chemical and petroleum engineering. Students should already have taken a first year course in thermodynamics. The refreshing approach and exceptionally rich coverage make it a great reference tool for researchers and professionals also. Contains International Units (SI).

### Textbook

The second edition of the book **Energy Systems: A New Approach to Engineering Thermodynamics** has been published by CRC Press in 2021.

The reader is explained how to build appropriate models to bridge the technological reality with the theoretical basis of energy engineering.

This volume is intended for courses in applied thermodynamics, energy systems, energy conversion, thermal engineering to senior undergraduate and graduate-level students in mechanical, energy, chemical and petroleum engineering. Students should already have taken a first year course in thermodynamics. The refreshing approach and exceptionally rich coverage make it a great reference tool for researchers and professionals also. Contains International Units (SI).