# StreamflowVL: A Virtual Fieldwork Laboratory that
## 1 Introduction
For example, [PERSON] et al. [39] developed an interactive, Web-based virtual laboratory with OpenGL technology to simulate and study fluid flow problems. By implementing finite volume methodology in the teaching software, they significantly enhanced the learning of fluid dynamics by undergraduate and graduate students, as the software can be used at home to solve other numerical problems in support of the coursework. Due to its generality, the tool can also be used by engineering professionals. [PERSON] et al. [40] introduced a three-dimensional model in a Hydraulics course at Tampere University of Technology (TUT), in Finland, using virtual reality modelling language (VRML) to teach the structures and functions of fluid power systems and hydraulic components. This technique showed students how a slide moved inside a valve and how it affected the opening of flow orifices, thus increasing or decreasing the flow. [PERSON] et al. [41] found a relationship between 2D and 3D animations, supporting the already mentioned schematic diagram-based 2D virtual hydraulic circuits, through VRML-based 3D virtual hydraulic equipment. The introduction of 3D experiments made the process of learning not only highly interactive and even more attractive, but also more effective in helping students to practise experimental operations. Recently, at the University of Belgrade Faculty of Mechanical Engineering Hydraulic Machinery and Energy Systems Department, [PERSON] et al. [42; 43] performed virtual experiments in the LabVIEW application for testing hydraulic pumps operating in parallel and series modes. This allowed students to improve their learning process through the analysis of various pump hydraulic curves, the study of their duty points, and the observation of the flow rates in each pipe. [PERSON] et al. [44] involved Engineering undergraduate students in the development of virtual labs in Fluid Mechanics using the LabVIEW platform. The experiments were created to track the profile of the jet trajectory from an orifice fitted in a tank and to draw the flow net for a given velocity potential stream function. The response of the students indicated that the virtual experience gave them a better understanding of the associated advantages and disadvantages and built their confidence. StreamflowVL, which is presented here, was built through the Unity 3D game engine and tested using a head-mounted display (HMD), called Oculus Rift, whose application was previously investigated by [45; 46; 47]. The interactivity with the real environment represents an innovative aspect of the proposed virtual laboratory compared to the VR tools developed so far in Hydraulic Engineering. A preliminary testing phase was carried out on a sample of students enrolled in the Master's degree course of Civil and Environmental Engineering program at Basilicata University, in order to validate the features and performance of the virtual didactic tool. Their feedback led to a series of updates to the final version. The paper is organised as follows: the importance of field studies in Hydraulics Engineering courses for graduated students is discussed in Section 2; the traditional approach to teaching the water discharge measurement procedure in open-channel cross-sections is presented in Section 3; the features, the conceptual design, and learning objectives of the proposed virtual laboratory are described in Section 4; the preliminary test results of a student's sample are highlighted in Section 5; a comparison with the traditional learning approach is detailed in Section 6; and the conclusion and future work plan complete Section 7.