Practical Source Code for Ship Motions Time Domain Numerical Analysis and Its Mobile Device Application

Abstract: This thesis included developing MATLAB program source code for the six degrees of rigidbody freedom time domain motions of a ship travelling with a specified mean velocity inwaves. The code is developed to simulate canonical forced and free motions. This studyfollowed the impulse-response function time domain method in which the hydrodynamiccoefficients are computed using the 2-D linear strip method in the frequency domain andconverted into the time domain. The equations of motion are then solved simultaneously.This study considers merchant ships except for ships with a buttock flow stern. Ikeda’sprediction is used for roll damping computation, and a good solution is achieved for vesselsother than buttock flow stern ships in roll motion. A range of wave periods and speeds arealso considered. Steady-state results are compared to other published results. The numericalmethod agrees with classical ship motions and published results.The present work explores ways to simulate ship motion in mobile devices. Two conceptsare proposed: web-based simulation (WBS) and a stand-alone simulation. The latterapproach is adopted. Two parts of the source codes are rewritten for the iOS platform: themotion related to memory forces and the calculation engine. The codes are tested in the iOSsimulator, and the results are compared with the MATLAB solution. The world’s first mobiledevice application in naval architecture achieves a good simulation result.