This study presents a validation of the OpenFOAM multiphase solver (i.e., multiphaseInterFoam) with respect to the elementary processes involved in the simulation of waves generated by high mobility subaerial landslide with a specific focus on the computation of energy terms. These processes include slide flow over a slope, impulse wave generation, wave dispersion, wave propagation and breaking. The simulations are conducted in 2D. The results allow to determine the minimum number of cells and the appropriate model tuning to reach acceptable accuracy while maintaining the computation time in a reasonable limit. To respect energy conservation, the choice of the turbulence model appears critical. Only, with a turbulence including a buoyancy term in the equations to account for the multiphase flow, and optimized initial values of the turbulence model parameters, could be the energy components of the flow accurately calculated. This study highlights the complexity of the phenomenon and the care with which, simulations should be conducted for the accurate computation of the energy transfers in the context of subaerial landslides.