# A hydrodynamic model of bridle towed system

Original article

## Abstract

To determine the parameters of bridle towed systems in preliminary design and describe the configuration and dynamic behavior of bridle cables during tow-ship changes its speed and course, a tug–cable–barge coupling motion model for bridle towed system is proposed. The governing equation of towing bridle was established based on finite difference method and the six-degrees-of-freedom equations of motion for tug and barge were adopted according to the MMG modeling theory. The dynamic coupling boundary conditions for bridle towed system are derived. The steady- state motion parameters of towing bridle were confirmed by double bisection method. The equations of towing bridle are solved by Newton iteration method. Tug and barge motion equations are solved by Runge–Kutta method. The computing results indicate that the model and algorithm in this paper can be used to predict the configuration and dynamic behavior, and determine the parameters in preliminary design of bridle towed systems.

## Keywords

Bridle towed system Towing bridle Steady-state motion Double bisection method

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