Numerical Calculations of Wave Growth and Decay Rates due to Wind

The turbulent air flow over water waves with varying wave slope, wave age and the Reynolds number is investigated using LES at both relatively low and high Reynolds numbers. For the present study, attention will also be paid to the case where waves propagate away from a storm into areas of lighter winds. The wave growth rates for the slow moving waves are found to depend strongly on wave slope while the decay rates for the fast moving waves are almost independent of wave slope. The critical value of wave age that marks this transition increases at the high Reynolds number.