(Moving this post from General to this more apt category)
Dear Dr. Jonkman,
Does OpenFAST yet model surface wind turbulence caused by ocean swells? This would entail a special inflow model. The effects could have significance to fatigue life of turbine rotors, and vary greatly according to location.
kPower followed the Makani GoogleX AWE R&D project from 2007 on. I got to meet and know the founders at their Alameda Island retired Navy base, which was near KiteShip where I trained and worked, based at North Sails’ old loft. kPower did constant Makani failure mode analysis, by which any complex system can be judged. When Makani pivoted offshore, due to problems like high noise and risk to populations, there was a basket of new challenges, like seabird poop fouling hot-running motor-gens, fouling laminar-flow wing surfaces, and even clogging critical pitot tubes.
A special area of concern stood out; launching and landing from a “perch” (spar buoy). Makani’s over-scaled M600 was already marginal with respect to reserve hover lift, and at risk of settling under power, where a ring vortex sets up around a rotor rather than a downward jet. kPower determined the risk was especially great during high ocean swells. These entrain air and create strong wind shear, the very same shear that enables albatrosses to Dynamic Soar (DS) the ocean. Thus, the Makani platform could find itself not just trying to dock on a heaving swaying perch, but perhaps literally have the air sucked out from under it.
Modeling a HAWT in such inflow wind shear seems like a reasonable goal, if its not being done already. The CFD is hyper-complex, as sea state, bottom interaction, and wind vary so many ways. Its a very interesting problem.