High-fidelity simulation of a novel rope-mesh structure for a floating photovoltaic array in waves

Abstract

Floating photovoltaic (FPV) systems offer a promising route for expanding solar generation in coastal and offshore water bodies. However, wave-induced motion, mooring loads, and inter-module forces govern their viability. Excessive motion reduces energy yield, amplifies connector and mooring tensions, and threatens long-term reliability, making accurate hydrodynamic prediction essential for design. Most current CFD studies focus on single-row floaters, typically barge or catamaran-type platforms connected by rigid or hinged connections, leaving the behaviour of multi-row FPVs with compliant inter-module connections largely unexplored. This study develops and validates a high-fidelity CFD framework for rope-mesh FPV arrays, implementing a novel in-memory spring-connector formulation within OpenFOAM's rigidBodyMotion framework to represent compliant, tensioned rope connections. The approach is validated against wave tank experiments for both single-module and 2×2 array configurations. Validation demonstrates excellent accuracy, with heave and pitch RAO errors within 5–13% across wavelengths. The framework successfully captures multi-body interaction effects, including wave-field shielding that reduces aft-row response by upto 10%. Direct comparison demonstrates that conventional rigid joints underpredict pitch by over 20% and overestimate heave by 18%, while the spring connector maintains errors within 5–13%, confirming the necessity of force-based compliant coupling for accurate rope-mesh FPV prediction. Connector force analysis reveals that streamwise connectors experience forces 3–5 times larger than transverse connectors, with peak forces occurring at λ/L ≈ 2.5–3.5, where phase differences maximise differential motion between rows. These results establish streamwise connections as the critical design drivers for rope-mesh FPV systems under head-sea loading.