Momentum flux measurements in the airflow over wind-generated surface waves

Boundary layer formulations in orthogonal curvilinear coordinates for flow over wind-generated surface waves

“…Specifically, we are interested in the airflow above surface gravity waves but do not consider waves with large curvatures such as capillary waves. Experimental results of airflow measurements over wind waves will be presented in the accompanying paper (Yousefi et al 2020). We note here that in the derivations above, the curvilinear system does not vary in time.…”

“…To this end, the measured velocity fields were projected and transformed into the curvilinear coordinate system, then averaged in the ξ 1 -direction. A detailed analysis of this experimental data is presented in the companion paper (Yousefi et al 2020). For the mean momentum equation in the ξ 1 -direction (4.27), for example, the complete dimensionless equation (in two dimensions) is…”

“…In appendix A, we provide the velocity-vorticity formulations in orthogonal curvilinear coordinates. Analyses of experimental data using the framework developed in this paper are presented in a companion paper (Yousefi, Veron & Buckley 2020).…”

Surface viscous stress over wind-driven waves with intermittent airflow separation

“…Later, Buckley & Veron (2016) and Buckley & Veron (2017) determined that separation dramatically enhances the along-wave turbulent stress and kinetic energy distributions past the crest of the average wind wave. Subsequent analysis is also presented in , Husain et al (2019) and Yousefi, Veron & Buckley (2020). Finally, two important laboratory studies that focused on estimating the near-surface viscous stress at the wavy air-water interface should be mentioned here.…”

A simulation-based mechanistic study of turbulent wind blowing over opposing water waves

“…Meanwhile, experimental and numerical studies have also examined the structures and effects of wave-induced turbulent stress in the wave boundary layer (e.g. Hsu, Hsu & Street 1981;Rutgersson & Sullivan 2005;Kihara et al 2007;Yousefi, Veron & Buckley 2020). While there still exists discrepancy in the wave growth rate between theoretical predictions and measurements (see the review by Sullivan & McWilliams 2010), the physical processes in the wind-following-wave case are relatively well understood, at least in a qualitative sense (Belcher & Hunt 1998).…”