A Method for Wave Driven Wind Simulations with CFD

A flexible open source based CFD method is developed in order to directly study the effects of the wave movement on the wind field in a neutral stratified atmosphere. Sea surface waves modify the wind field in the marine atmospheric boundary layer (MABL) in different ways. Long periodic waves (swell) resemble a sinusoidal wave. The flow responses over this sinusoidal wave are studied in detail by the use of a moving grid approach. Waves aligned with the wind and opposed the wind are studied. Simulations show that a fast moving swell aligned with the wind will speed up the wind in the lowest meters of the MABL, whereas a fast moving swell opposed to the wind field will reduce and even revert the wind speed in the lowest meters. Swell opposing the wind field will also generate more turbulence in the lowest meters of the MABL than when waves and wind are aligned with each other. The simulations are compared with a logarithmic wind profile and wave influence causes the wave induced wind profiles to deviate from the logarithmic shape, especially in the case where swell is opposing the wind.