FY 1986

Icing of Ships. Part I: Splashing a ship with spray

Zakrzewski, W.P.

NOAA Tech. Memo. ERL PMEL-66, NTIS: PB86-190147/XAB, 74 pp (1986)

Wind- and wave-generated spray fluxes to an object (cylinder and vertical plate) located on and above the deck of a medium-sized fishing vessel (MFV) are investigated. Using formulas derived for a fully arisen sea, sea-state was defined by the significant wave height, which is a function of wind speed and fetch. Formulas for the liquid water content (LWC) of wind-generated spray are reviewed. It was found that wind-generated spray does not affect an object located on and above the deck of a MFV. Such spray may affect only small ships with low freeboard and low bows in strong winds. Wave-generated spray is the one and only source of water delivery to an object if rain, drizzle, snow, fog, and the flooding of a ship deck by waves is neglected. The wave-generated spray flux was defined using derived formulas of the vertical distribution of the LWC and time of ship exposure to spray originating from spray cloud induced by ship/wave collision. These formulas were derived using published data on a Russian field experiment in the Sea of Japan. The time-averaged water flux to an object can be computed for any given wind speed, fetch, ship speed, and heading angle. These results are applicable for calculating the ice growth rates on medium fishing vessels.