Development and validation of a multi-segment rod model for underwater towing system

The underwater towing system is widely used in the measurement of underwater noise and the exploration of natural resources. In underwater detection, the attitude of the underwater towing system greatly influences the detection accuracy. Therefore, it is important to accurately predict the attitude of the towing system during its design and application. In this paper, the force and moment equilibrium equations for the towing cable and the towing array are established by analyzing the steady-state of the towing system. The iterative solution method for nonlinear equations is used to solve the problem, leading to a rapid prediction based on the multi-segment rod model. Since the attitude is significantly affected by the drag coefficient, selecting an appropriate drag coefficient has always been a challenge. In this paper, a drag coefficient formula is established by fitting experimental data. Based on the muti-segment rod model and the drag coefficient formula, an attitude prediction method for the towing system is developed. The results are validated through experiments and examples from the reference, confirming the accuracy of the modeling method and the drag coefficient. The influence of each parameter of the towing system on its steady-state motion is studied.