(238e) The Virtual Sandbox: Particle Flow Physics Taught with Interactive Tools

Processes in the chemical industry involving particles and powders are (i) difficult to describe, and (ii) often pose a risk for process stability and safety. To guarantee process and product safety, process simulation, as well as the simulation of particle flow, became a main trend over the past decades. Accordingly, there is a strong need to cover the simulation of particulate systems in basic and advanced courses of particle technology and multiphase reactors. The virtual sandbox project focuses on the adoption of the augmented reality sandbox presented by Reed et.al. (2014) for teaching the basics of particle flow physics. It comprises a sandbox, a Kinect camera, and a simulation program. The sand surface is scanned, and loaded into the particle simulator LIGGGHTS®. The simulation results can be projected onto the sand to close to loop from reality to simulation, and back to reality.

The deeper scientific meaning of the project can be summarized as follows: the first key element is to teach the students the importance and comfort to simulate particle based processes, rather than performing experiments which suffer from the opaque nature of sand. The second element is to introduce the complexity and the effect of liquid bridges that exist between individual grains. Our idea is to guide the students through a set of models that are needed to describe these bridges: starting with models that describe the genesis of a pendular bridge (Wu et al., 2016), over the seminal work of Halsey and Levine (1998) on roughness effects, to the most recent developments in force models. Third, basics concepts of 3D vision are introduced, in order to make students aware of the enormous capabilities of modern camera systems. Last but not least, new teaching methods, e.g., inquiry-based learning, are developed and applied to the above topics: via additional small-scale and easy to reproduce experiments we make an attempt to illustrate the above scientific concepts even to high school students (age 16 to 18), as well as primary school pupils (age 6 to 10).

Acknowledgement
The project is founded by the Austrian Science Fund FWF WKP67.

References
T. Halsey, A. Levine, "How Sandcastles Fall", Physical Review Letters 1998, 80, 3141-3144.

S.E. Reed, L. Kreylos, S. Hsi, L.H. Kellogg, G. Schladow, M.B. Yikilmaz, H. Segale, J. Silverman, S. Yalowitz, and E. Sato, "Shaping Watersheds Exhibit: An Interactive, Augmented Reality Sandbox for Advancing Earth Science Education", Americal Geophysical Union, Fall Meeting 2014.

M. Wu, S. Radl, J.G. Khinast, A model to predict liquid bridge formation between wet particles based on direct numerical simulations, AIChE Journal 2016,62, 1877-1897.