Real-Time Immersion of Physical Experiments in Virtual Wave-Physics Domains

We immerse a two-dimensional physical wave-propagation experiment in a virtual (simulated) environment in real time. This enables broadband hybrid wave experimentation in physical media that may be governed by unknown physics, embedded seamlessly within virtual media with either modeled or measured physics. Using the theory of immersive boundary conditions and a recently presented control system [Becker et al., Immersive Wave Propagation Experimentation: Physical Implementation and One-Dimensional Acoustic Results, Phys. Rev. X 8, 031011 (2018)], we convert a circular two-dimensional acoustic waveguide into a larger physicovirtual square waveguide. Real-time wave-field extrapolation allows waves to propagate seamlessly between physical and virtual media, producing correct wave-field interactions between them, including nonlinear effects. We show that the laboratory can physically measure the response of nonphysical energy-gain materials in real time. The physicovirtual laboratory thus allows previously inaccessible wave phenomena to be investigated experimentally and constitutes an alternative approach for wave-physics investigations by connecting experimental and numerical approaches.