CFD Analysis on Course Stability of An Asymmetrical Bridle Towline Model of a Towed Ship
Keywords:course stability, CFD, slewing motion, towing angle, towing velocity
Ship towing system has been widely applied to tow disable ship at sea. However, employing improper towing configuration may lead to towing instability presented in the form of the excessive fishtailing motion. To ensure ship’s safety navigation, therefore, a comprehensive assessment on course stability performance of a towed ship is necessarily required. This paper presents the course stability analysis of the towed ship (barge) incorporated with an asymmetrical towing configuration of towline model in calm water. Here, Computational Fluid Dynamic (CFD) has been successfully conducted to achieve the objective. Several towing parameters such as towing angle and towing velocity have been accordingly taken into accounts. The results revealed that the increase of towing angle up to 35o has reduced significantly the sway motion amplitude of barge by 94.6%. However, the increase of towing velocity from 0.655 m/s to 0.728 m/s was insignificant effect to the magnitude of the yaw motion of the barge. It is merely concluded that the increase of the towing angle associated with low towing velocity has remarkably improved the course stability of the barge. These findings are very useful for a better navigational safety guidance of the ship towing system.