Modelowanie charakterystyki prędkości jednostki ze śrubami nastawnymi na podstawie wyników badań

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.