Relationship of the Frequency and Time Domain with Respect to Ship-Motions

摘要

In this report the relationship of the frequency and time domain expressions for211u001ethe hydromechanical reaction force, that act on the hull of an oscillating ship, 211u001eis presented. The report is based on the theory developed by Cummins and Ogilvie 211u001ein the early sixties. The boundary value problem for unsteady shipmotion is 211u001ederived and linearized. Solution forms to this boundary value problem are 211u001eproposed in the frequency and the time domain. The hydromechanical reaction force 211u001eon the ship hull is expressed in terms of these solutions. Some theory on the 211u001eresponse of linear systems and the relationship of the frequency and time domain 211u001eis presented. This theory is applied to the two expressions for the 211u001ehydromechanical reaction force. A relatively easy way to find the constants and 211u001ethe impulse response function (Retardation function), that appear in the time 211u001edomain expression, is proposed.