Abstract
Wave energy has enormous potential as a renewable energy resource, but characterizing device and mooring line behavior in deep-water regimes is difficult due to the size constraints in traditional laboratory testing. A real-time hybrid simulation (RTHS) framework is proposed to emulate deep-water mooring lines in reduced-scale experiments. RTHS couples physical experiments with numerical models to virtually deepen existing hydrodynamic facilities. In the proposed framework, a small-scale wave energy converter (Sub-WEC) will be physically tested in the Large Wave Flume at Oregon State University. The mooring line will be numerically simulated using MoorDyn, which will send commands to a motor to emulate tensions on the line, representative of the device placed in deep-water regimes. Sensor measurements of Sub-WEC will then serve as inputs to update the next iterative state of the numerical model. To validate the feasibility of the hybrid approach prior to flume testing, the study herein examines a virtual-RTHS framework using numerical proxies to virtually rehearse the communication and data exchange between the numerical and physical sub-assemblies. The communication architecture uses a modular, three-loop architecture for improved synchronization. A numerical model represents the actuation motor, derived from governing equations of motion and system identification. An estimation procedure of the parameters in the equations of motion as well as discrepancies in the numerical model and experimental data are discussed. This virtual framework provides a means of testing the communication architecture prior to flume testing, with future work involving fine tuning the actuator model to obtain a more realistic virtual simulation.
The poster associated with this paper from UMERC/OREC 2025 can be found here.