Abstract:

In this work, the authors show an experience in the field of science, technology, engineering, and mathematics (STEM) education applied to the subject "Thermal Machines," which is in the curricula of the Bachelor's degree in Mechanical Engineering at the University of Jaén (UJA). Several software applications used during the lab sessions to improve the subject's dynamic will be described.

Lab sessions play an important role in the development of a subject since they consist of problem-based learning cases where data must be obtained from experiments. Theory and problem lessons make the students learn the basic concepts and methods of the subject. Later, they get close to reality in lab sessions. Nevertheless, there is not enough time to do experiments and analyze their results conveniently. In a one-hour (or two-hour) lab session, it would be required:
i) An initial explanation of the problem to be solved, including theoretical, experimental, and methodological tasks (in any case, the required documentation must be provided previously, so students might attend the lab knowing the basics concepts).
ii) Carrying out the experiment, handling equipment, and taking measurements.
iii) Calculations and assessment, with the teacher's supervision.

Finally, the student may be required to choose between the following alternatives:
i) fill out a final form and give it to the teacher,
ii) finish the calculations and analysis at home and submit the corresponding report. This option lengthens the time spent by the student on the task and makes it more difficult, as the student does not have the teacher's supervision.

The teacher is forced to define a few laboratory sessions in the course design to adjust to the ECTS credits assigned to the subject. To overcome these difficulties, the presented experience proves the usefulness of providing students with some computer tools (through several spreadsheets and scripts of scientific calculation software) as complementary material. Each file includes the required equations required to operate with the measured experimental data at each session. It is important to highlight that the students know those equations and methodology. Furthermore, since they can perform the necessary calculations and analysis faster, the dynamic of the lab sessions is improved, and it is possible to:
i) finish all the required procedures at the end of each session, avoiding leaving associated tasks for later;
ii) extend the number of laboratory practices to be carried out within the subject (up to 9) supporting the study of positive-displacement machines, such as internal combustion engines or compressors, turbomachinery, and gas turbines;
iii) guarantee the teacher's supervision during each case study, fostering the teacher-student interaction.

As a result of applying the presented experience during the last ten academic courses, higher motivation and academic performance have been observed compared to previous subjects with similar contents where those tools were not provided.

Keywords:

Calculation tools, thermal machines, lab sessions.