Experimental investigation of the airflow structure above mechanically generated regular waves for both aligned and opposed wind-wave directions
Porchetta, S.; Carlesi, T.; Vetrano, M.R.; van Beeck, J.; Laboureur, D. (2022). Experimental investigation of the airflow structure above mechanically generated regular waves for both aligned and opposed wind-wave directions. Experimental Thermal and Fluid Science 133: 110578. https://dx.doi.org/10.1016/j.expthermflusci.2021.110578 In: Experimental Thermal and Fluid Science. ELSEVIER SCIENCE INC: New York. ISSN 0894-1777; e-ISSN 1879-2286, more |  |
| Keyword | | | Author keywords | Air-sea interactions; Wind-wave interaction; PIV; Aligned-opposed wind-wave direction; Wind-wave tunnel |
| Abstract | A better understanding of the wind–wave direction effect on the wind field and on the momentum transfer at the air–sea interaction will aid in the development of numerical atmospheric and wave models, important for wind energy studies among other applications. So far, the effect of opposed wind–wave directions on the wind field is not fully understood, even though it is shown to be an occurring phenomenon at the air–sea interface. To investigate the effects of different wind–wave alignments on the wind field and on the momentum transfer, the Wind Gallery of the von Karman Institute (VKI) was modified in order to perform aligned and opposed wind–wave direction experiments. The measurements performed to define the wind field and momentum transfer consisted of a Particle Image Velocimetry (PIV) setup with one laser and one camera. Based on this setup, differences in horizontal and vertical wave perturbation velocity as well as in phase-averaged wave-perturbation stress or momentum were observed between aligned and opposed wind–wave directions in terms of location, structure and vertical depth. This study thus provides support that the wind field and phase-averaged wave-perturbation momentum are dependent on the wind–wave alignment, which in the future should be accounted for in numerical models. |
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