The slam force on a flat plate in free flight due to impact on a wave crest

An experimental investigation of the maximum vertical force on a flat plate in free flight due to impact on water waves has been made. The plate is horizontal and impacts a wave crest at mid-length. The mass, impact velocity, flight path angle and wave steepness were varied. A slam force coefficient based on dimensional concepts and physical reasoning is produced which is well described by a formula which omits the effects of acceleration due to gravity, water and air compressibility and surface tension. High-speed video was used to visualize the jets produced at impact, showing them to have high velocity and a fine droplet structure. (C) 1998 Academic Press Limited.