Search

This paper presents an analysis of the acceleration of a fast boat using a simulation model. Mathematical equations of ship motion dynamics with two types of propeller capabilities are developed using MATLAB and Simulink as simulation tools. The equations are extended to include the acting thrust, resistance, propeller’s performance curves, and the PID governor curve for the acceleration manoeuvre. The application models the dynamic differential equations representing the vessel dynamics in one degree of freedom. MATLAB code was used to develop the ship acceleration as a multibody system. Modules of hydrodynamic forces, resistance, moments, and propeller performances were implemented to simulate the ship manoeuvring process. A comparison of the results for the boat’s propulsion performance with two different propellers and the characteristics of the PID governor, which controls the fuel dose in the gas turbines, was carried out. We present a summary including a comparative analysis of the results for the boat dynamics with and without the PID governor. The results obtained here confirm significant discrepancies between the results of numerical simulations with and without the PID governor.

Divers’ underwater performance is directly related to their swim-fi n effi ciency. To determine the effi ciency, a comparison is needed between existing models of swim-fi ns leading to conducting experiments that yield reliable results and promise an optimal model. One method of comparison is to construct an automated system that would be able to mimic human leg movement in a submerged environment during independent experiments. To mimic this human behaviour, the options are to either move the robotic leg in the swimming pool or have water fl ow around it in a water tunnel. The second mechanism is simpler to construct and develop because it includes fewer mechanical parts and can be built as a stationary test bench. Therefore, this paper reports the development of this mechanism. Its controlling system is designed based on movement patterns obtained using computer vision techniques in addition to analyses of diver’s behaviour during initial experiments. The presented solution has the potential for comparing the effi ciency of a range of swim-fi ns in a short time. [ABSTRACT FROM AUTHOR]