Experimental Investigation of a Wave-Piercing Trimaran on the Outrigger Configurations in terms of Seakeeping and Added Resistance

Abstract

The outrigger symmetry of a trimaran is believed to significantly affect its hydrodynamic functioning. The present study was conducted to investigate the added resistance responses and experimental vertical motion of a wave-piercing trimaran in regular head waves. A series of experiments have been carried out in the National Iranian Marine Laboratory (NIMALA) towing tank to determine the effect of side hulls symmetry on the heave and pitch motions and added resistance. The models were tested over a range of wave frequencies and Froude numbers using both symmetric and asymmetric outriggers. According to the results, the symmetric side hull form based on heave motion, the outboard form in terms of pitch motion and added resistance have better performances among these three kinds of side hull forms. Furthermore, there are local maximum and minimum points on the ship motion response curves due to heave and pitch coupling in their respective frequencies.