Generalized Nonlinear Time Domain Motion Predictor for SWATH Craft

摘要

A generalized nonlinear time domain simulation model development for SWATH craft is described. The model, as developed, considers motion in the pitch-heave, degrees of freedom only. There is no technical impediment to expanding this to the full six degrees of freedom of rigid body motion. As contrasted with a frequency domain simulation currently used for predicting motions of SWATH craft, the generalized nonlinear time domain simulation will accept any non-pathological function of time as a forcing function. Also frequency independent nonlinearities are easily accommodated. For linear situations, motion predictions made with both the frequency domain simulation and the generalized time domain simulation show sensibly identical agreement. Where the generalized time domain simulation is used in a manner that reveals the full effects of nonlinearities (the frequency domain simulation linearizes), there, as would be expected, are differences between the predictions made with the two simulations. (Author)