The existence of a moonpool may affect motion characteristics and stability drillship. This paper presents numerical experimental study on the influence configuration performance drillship under condition constant displacement. Ship hydrostatics three-dimensional (3D) potential flow theory are employed to calculate static curves (GZ curves) response amplitude operators (RAOs) with conjoined dou...

The placement of artificial reef (AR) units on the seabed modifies velocity field water, making nutrients circulate properly and creating necessary habitat for settlement desired species. This paper proposes a methodology determining circulation in vicinity one specific AR unit module previously defined existing literature. has been based both application three-dimensional hydrodynamic criteria...

The 1978 ITTC Power Prediction method is used to predict the propulsive power of ships through towing tank testing. form factor approach and its determination in this have been questioned. This paper investigates possibility improve predictions by introducing Combined CFD/EFD Method where experimental replaced double body RANS computations applied for open cases KVLCC2 KCS, including first-time...

This paper studies trajectory generation for a mothership that tows a drogue using a flexible cable. The contributions of this paper include model validation for the towed cable system described by a lumped mass extensible cable using flight data, and optimal trajectory generation for the towed cable system with tension constraints using model predictive control. The optimization problem is for...

This work concerns the dynamics of towed array lifting devices (LFDs), which help to maintain the position of a tow line being dragged behind a vessel. The LFD satisfies the non-dimensional quadratically damped Mathieu equation ẍ+ (δ + 2 cos t)x+ ẋ |ẋ| = 0. Numerical study of this equation shows a wide array of dynamical features. The dynamical features of the system are exploited to obtain a c...

This paper deals with the attitude control of a towfish (underwater towed vehicle) two elevators and single rudder to improve image quality an attached sound navigation ranging (sonar) system. Image distortion can occur if shakes excessively. Since is connected mother ship through towing cable motion affected not only by cable, but also position center gravity, point, speed, it necessary analyz...

The hydrodynamic performance of one full-scale T0 (mesh size 90 mm) and three T90 90, 100, 110 codends was investigated compared using flume tank testing, with without a small-mesh cover. We evaluated how flow velocity, mesh circularity, drag changed in each codend at five different towing speeds (0.5–0.9 m/s). results demonstrated that velocity decreased along the length codend, this effect pr...

The discharge of ballast water may introduce and transport unwanted marine organisms to the discharging area. Marine Environment Protection Committee (MEPC) IMO consider action as hazard due possibility having negative impact on receiving ecosystems. Many researchers have investigated possible solutions for management minimize risks including free system. concept system is replace conventional ...