Study on hydrodynamic characteristics and depth control of the towed sensors array system

Abstract

The hydrodynamic characteristics and depth control of the towed sensors array system (TSAS) are investigated based on lumped mass method and computational fluid dynamics (CFD). Firstly, the flexible towed cable is discretized into multiple rigid links with the lumped mass point, and the terminal point is the towed underwater vehicle (TUV). Coupling analysis of each sensors integrated module to a finite length of towed cable is performed, taking the module as the lumped mass point. The variation of normal and tangential forces with the change of angle are discussed for different towed speeds. Then, the dynamics model of the TUV is established and solved. The equilibrium equation for each lumped mass point is established using the recursive method from the bottom up. The angle between each link and the horizontal plane is calculated. Finally, the coordinate of each node is derived, and the position of the towed cable is fitted. The study shows that the hydrodynamic characteristics of the module and towed cable significantly impact the depth control and profile measurement. Sea trials validate the reliability of the method proposed in this paper, which is a guide to the design and manipulation of the TSAS.