Abstract:

Hydraulic Engineering is a subject of great relevance in many Degree Programs of Technical Schools. In this kind of subjects, experimental and practical training appear as an essential complement of theoretical fundamentals, studied and analyzed in the classroom in depth. Nowadays, the development of e-learning platforms which are being implemented in many universities facilitate enormously the possibility to introduce new teaching models which allow the combination of traditional on-site laboratory assignments with other learning assignments conducted autonomously on-line by students.
In practice, the characterization of hydraulic elements requires the measurement of qualitative and quantitative variables through a suitable experimental procedure. One of the most innovative experimental approaches relies on Particle Tracking Velocimetry (PTV). This is a non-intrusive technique which allows the determination of the instantaneous flow fields with high spatial resolution. It makes possible the detection of spatial structures in unsteady flows quantitatively, which is not possible with other experimental techniques. In PTV, tracer particles have to be added to the flow. A two-dimensional slice of the flow is illuminated by a laser sheet and the light scattered by the particles is recorded. These images are digitized and after processing them, the experimental flow field can be obtained and visualized.
This paper describes a practical session of the subject ‘Hydraulic Engineering’ focused on the flow analysis in a gate-valve. A PTV approach is used to determine the average and instantaneous speed fields under different flow conditions. This experimental assignment is very suitable for a real display of vortitial structures and their movements as well as of the development of current lines. PTV technique has recently been applied in a relevant number of researches in very different areas of fluid mechanics.
After the on-site experimental session, the students will have at their disposal the results of these sessions through information technology applications, in order to use this information as support material of theoretical sessions.
The practical session described in this paper pursues a new contextualization where the student assumes an active role and adapts the learning process to its own personal abilities. Here, the experimental results are added as a didactic support resource in a digital format to the e-learning platform of the university (PoliformaT). From this moment on, the student is able to access the theoretical fundamentals of the subject as well as experimental results and pictures of the sessions described. Finally, the proposed practical experience would result of great interest for the students. Moreover, it would allow them to get in contact with the experimental techniques used in some of the research works developed at the University.

Keywords:

autonomous learning, didactic support resource, practical training, e-learning.