Time Domain 3d Wave Loads Calculation Of Ships With Forward Speed Based On Rankine Panel Method

Establishing wave loads of floating body with forward speed is a tough task of the marine industry. Although the relavant theory was presented several decades ago, there are few reliable methods can be applied for practical usage. As the speed of ships is getting much more faster, as well as the coupling of waves and current in offshore engineering industry; solving the forward speed problem is very important. This dissertation is based on practical consideration, and the widely used time domain Rankine panel method is utilized to solve the motion and wave loads of floating body with forward speed. The major works are as following:1. Investigate the application of Rankine source method and quadratic B-spline theory in solving the hydrodynamic problem with forward speed. The radiation conditions due to the truncation of free surface are also studied; the numerical beach and collocation method are applied.2. Both Kelvin-Neumann and Double-body are used for linearization of free surface condition. The transom stern hull is taken into consideration as well, and a specified numerical method is utilized to compute the m j terms.3. Compute the responses of floating body in regular waves, the spring system and autopilot are chosen to control the transverse motion. The wave pattern and forces are studied with respect to numerical beach parameters.4 Computation of forced motion of a cargo ship is performed and the hydrodynamic coefficients are compared with those obtained via free surface green function method.5. The numerical damping, dispersion and stability are investigated. The free motion is calculated by using a container ship in order to study the relationship between input information such as time step, mesh size, speed and the floating body's responses.