The effects of smoothing length on the onset of wave breaking in smoothed particle hydrodynamics (SPH) simulations of highly directionally spread waves

Ocean wave breaking is a difficult-to-model oceanographic process, which has implications for extreme statistics, the dissipation of energy, and air–sea interaction. Numerical methods capable reliably simulating real-world directionally spread waves are useful investigating physics design offshore structures floating bodies. Smoothed particle hydrodynamics modelling highly steep overturning free surfaces, makes it promising method waves. This paper investigates effect smoothing length on simulated in both following crossing seas. To do so, we reproduce numerically experiments McAllister et al. (J Fluid Mech 860:767–786, 2019. https://doi.org/10.1017/jfm.2018.886 ) using range normalised lengths: $$h/d_p=1.4$$ , 1.7, 2.0, 2.3, with h $$d_p$$ spacing. The smallest use appears to adversely affect fidelity surface elevation, so that tallest crest observed not fully reproduced (coefficient determination $$r^2\approx 0.7$$ ). For lengths $$h/d_p=1.7$$ well ( $$r^2\ge 0.88$$ ); these simulations predominantly affects spatial extent duration breaking. Qualitative quantitative comparison our shows values $$h/d_p$$ $$1.7{-}2$$ best phenomena experiments.