The Lindqvist method is adopted to estimate the ice resistance for an icebreaker.The accuracy of the method is evaluated in a comparison of the calculated results with model test results.In addition to the estimation ...The Lindqvist method is adopted to estimate the ice resistance for an icebreaker.The accuracy of the method is evaluated in a comparison of the calculated results with model test results.In addition to the estimation of ice resistance,a sensitivity analysis based on the Lindqvist method is carried out.A full parametric model developed using CAESES software allows the convenient construction of many new hull lines.The primary factors relevant to ice resistance are embedded as design parameters in the full parametric model.Meanwhile,response surface methodology is adopted to give better insight into new hull lines.Results show that the ice resistance is more sensitive to the rake angle and waterline entrance angle.The aim of the present study is to improve the techniques of designing the hull forms of icebreakers.展开更多
In a modern electrical driver, rotor field oriented control an appropriate transient response. In this method, the space （RFOC） method has been used to achieve a good performance and vector of the rotor flux comes h...In a modern electrical driver, rotor field oriented control an appropriate transient response. In this method, the space （RFOC） method has been used to achieve a good performance and vector of the rotor flux comes handy by the rotor resistance value. The rotor resistance is one of the important parameters which varies according to motor speed and room temperature alteration. In this paper, a new on-line estimation method is utilized to obtain the rotor resistance by using Walsh functions domain. The Walsh functions are one of the most applicable functions in piecewise constant basis functions （PCBF） to solve dynamic equations. On the other hand, an integral operational matrix is used to simplify the process and speed of the computation algorithm. The simulations results show that the proposed method is capable of solving the dynamic equations in an electrical machine on a time interval which robustly estimates the rotor resistance in contrast with injection noises.展开更多
文摘The Lindqvist method is adopted to estimate the ice resistance for an icebreaker.The accuracy of the method is evaluated in a comparison of the calculated results with model test results.In addition to the estimation of ice resistance,a sensitivity analysis based on the Lindqvist method is carried out.A full parametric model developed using CAESES software allows the convenient construction of many new hull lines.The primary factors relevant to ice resistance are embedded as design parameters in the full parametric model.Meanwhile,response surface methodology is adopted to give better insight into new hull lines.Results show that the ice resistance is more sensitive to the rake angle and waterline entrance angle.The aim of the present study is to improve the techniques of designing the hull forms of icebreakers.
文摘In a modern electrical driver, rotor field oriented control an appropriate transient response. In this method, the space （RFOC） method has been used to achieve a good performance and vector of the rotor flux comes handy by the rotor resistance value. The rotor resistance is one of the important parameters which varies according to motor speed and room temperature alteration. In this paper, a new on-line estimation method is utilized to obtain the rotor resistance by using Walsh functions domain. The Walsh functions are one of the most applicable functions in piecewise constant basis functions （PCBF） to solve dynamic equations. On the other hand, an integral operational matrix is used to simplify the process and speed of the computation algorithm. The simulations results show that the proposed method is capable of solving the dynamic equations in an electrical machine on a time interval which robustly estimates the rotor resistance in contrast with injection noises.
