SPH numerical investigation of the velocity field and vorticity generation within a hydrofoil-induced spilling breaker

In the present work, the velocity field and the vorticity generation in the
spilling generated by a NACA 0024 hydrofoil were studied. SPH simulations were
obtained by a pseudo-compressible XSPH scheme with pressure smoothing; both an
algebraic mixing-length model and a two-equation model were used to represent turbulent
stresses. Given the key role of vortical motions in the generation of the spilling breaker, the
sources of vorticity were then examined in detail to confirm the interpretation of the mean
flow vortical dynamics given in a paper by Dabiri and Gharib (J Fluid Mech 330: 113–139,
1997). The high precision of the SPH model is confirmed through a comparison with
experimental data. Experimental investigations were carried out by measuring the velocity
field with a backscatter, two-component four-beam optic-fiber LDA system. The agreement
between the numerical results and laboratory measurements in the wake region is
satisfactory and allows the evaluation of the wave breaking efficiency of the device by a
detailed analysis of the simulated flow field.