Investigation of the static trim angle effects on the hydrodynamic performances of a semi-planing catamaran in calm water and waves

This article uses the model test to investigate the effect of static trim angle on the hydrodynamic performance of a semi-planing catamaran named AUT-SEM00. First, the resistance test results in the calm water at different speeds for static trim angles of 0.00 to 4.00 degrees are presented. The best static trim angle hence the lowest resistance is 2.0o at a speed of 3.78 m/s which leads to the dynamic trim of 2.5o. Then, the model test in three regular waves in a range of static trim angles is conducted, and the results are analyzed. It has been seen that the best static trim angle in comparison to the other rim angle depicts up to 9% less resistance. Additionally, it is shown that the static trim angle does not significantly affect pitch motion and vertical accelerations. As far as the regular wave length is concerned, the pitch and accelerations on CG and FP rapidly increase as wave length increases. There is a strong correlation between vertical acceleration and pitch motion where both have the same tendency concerning the wave length.