Modeling of the Speed Characteristic of the Ship with the Control Pitch Propellers Based on Research Results

Abstract

The paper presents the process and results of selecting the speed drive characteristics model for a two-shaft ship with control pitch propellers. Three forms of models of characteristics were formulated: a polynomial created by the stepwise approximation method, a second degree power polynomial applied directly, a second degree power polynomial built stepwise, a polynomial (monomial) with real powers. Numerical models were determined using the least-squares method, guided by the minimum sum of squared deviations. As a result of rejecting the three points as excessively deviating, calculations were also made for the twelve-point set. Next, the behavior of the models at the boundary points, which are zero pitch, zero revolution and zero speeds of the ship, were estimated. As a result of the conducted analyses, it was recognized that the right model may be a model with real powers, and the next model is a power polynomial built using a stepwise method.nsport of a two-phase mixture was also discussed.