Maruo's theorem

Added resistance in regular waves due to hull motion, , from Maruo's theorem^* as follows:

where;

: Fluid density; : Gravity acceleration; : Ship's speed; : Incident regular wave frequency; : Wave direction (0 degrees head wave);
is a function defined by the singularity distribution and represents the periodic disturbance caused by the hull.

^*Reference
H. Maruo: Resistance in Waves, Research on Seakeeping Qualities of Ships in Japan, The Society of Naval Architects of Japan, Vol.8, pp.67-102, 1963.