Abstract
This paper extends a hybrid model qaleFOAM to assess the nonlinear interaction of waves with an array of point-absorber wave energy converters (WECs). The hybrid model uses an adaptive one-way coupling strategy, combining a two-phase Navier–Stokes (NS) solver interDyMFoam with the fully nonlinear potential theory (FNPT)-based solver QALE-FEM. To minimise the computational cost, an improved wave absorbing technique is adopted to absorb the undesirable reflected waves at the inlet/outlet boundary of the NS domain instead of using the conventional relaxation zone technique. The model is first assessed against available single-buoy benchmark data, and then applied to regular head-wave cases involving CorPower-type buoys arranged in line arrays. The effects of wave steepness, PTO damping and non-dimensional array spacing are examined. For the two-buoy cases, increasing wave steepness increases the mean surge and pitch drifts and enhances the asymmetry of the instantaneous absorbed power, while reducing the normalised first-harmonic motion amplitudes. Increasing PTO damping reduces the heave response but increases restraint forces and power fluctuations, and may promote overtopping under the studied conditions. For the three-buoy cases, the q-factor and the absorbed power of each buoy vary non-monotonically with non-dimensional spacing d/λ, with the minimum q-factor observed at d/λ ≈ 0.5. Shorter waves produce stronger shielding effects on the middle and rear buoys, affecting both hydrodynamic loads and tether-force fluctuations. These results demonstrate that, within the tested configurations, nonlinear wave effects, PTO damping and array spacing can influence motion response, power absorption and load distribution among buoys.