A virtual laboratory for conducting “hands-on” experiments on water wave mechanics

Abstract

Water wave mechanics are an important topic for scientist and practitioners of civil engineering due to the key role in coastal structure design and the understanding of beach erosion and coastal flooding. Different water wave theories have been proposed over the past two centuries to describe wave transformation, being the so-called linear water wave theory; the most fundamental but still widely used despite its limitations. The use of laboratory facilities in water wave courses, at both undergraduate and graduate levels, is fundamental to provide hands on experience and training on the experimental design and data analysis. Furthermore, it allows to evaluate the validity and limitations of linear wave theory. Unfortunately, such facilities are scarce and their use was further complicated owing to social distancing measures during the COVID-19 outbreak. On the other hand, the advent of computer technology and Computation Fluid Dynamics codes have allowed the development of virtual laboratories for science, technology, and engineering. Here, a widely validated numerical model, which solves the Reynolds Averaged Navier-Stokes (RANS) equations, is employed to develop a virtual wave flume for educational purposes. The virtual laboratory consists of three components: 1) An educational component consisting of lab assignments including background theory, mainly based on the water wave mechanics book by Dean and Dalrymple (1991), and the description of the experiment to be conducted in the virtual wave flume; 2) Synthetic data, corresponding to different RANS simulations, including the spatial-temporal variability of different hydrodynamic variables corresponding to realistic laboratory experiments; and 3) The Graphical User Interface (GUI) allowing the user to select the experiment and download the lab assignment instructions. Within each experiment the user may select different wave conditions and deploy the virtual “sensors” interactively. The experiment and time series corresponding to the virtual sensors can be visualized in real-time. The data acquired with the virtual sensors can be exported as a binary file for further analysis and comparison with theory. The virtual laboratory has been employed as a supporting tool in the Water Wave Mechanics and Nearshore Hydrodynamics graduate courses taught at the National Autonomous University of Mexico. A preliminary assessment of learning outcomes revealed that students agree on the usefulness of the virtual wave flume to the understanding of wave transformation processes and the enjoyment of the courses. The documentation, pre-run numerical simulations, and GUI are integrated in a self-application program developed in Matlab® available for download from a public repository.