International Shipbuilding Progress - Volume 58, issue 4

Authors: Rijkens, A.A.K. | Keuning, J.A. | Huijsmans, R.H.M.

Article Type: Research Article

Abstract: An effective method to reduce the violent motion behaviour of fast planing vessels in waves may be found in the application of active control devices in conjunction with advanced motion control systems. This study aims to develop a computational tool for the design and optimization of these ride control systems for high speed planing monohulls. Hydrodynamic characteristics of both transom flaps and interceptors are determined by systematic series of model test experiments in the towing tank of the Laboratory of Ship Hydromechanics at the Delft University of Technology. Transom flap results at downward deflection angles are validated with formulations found …in literature. In addition, experiments at up angle flap positions have been performed to increase the range of application for motion control purposes. The hydrodynamic performance of the interceptors and transom flaps are compared in order to determine their efficiency. The experimental data was implemented in a nonlinear time domain mathematical model that can predict the seakeeping behaviour of fast monohulls. Simulations demonstrate the improvement in motion behaviour of a fast planing vessel with a ride control system sailing in head waves. Show more

Keywords: Ride control systems, transom flaps, interceptors, planing vessels

DOI: 10.3233/ISP-2012-0074

Citation: International Shipbuilding Progress, vol. 58, no. 4, pp. 165-190, 2011

Authors: Bhattacharyya, S.K. | Rajesh, G. | Gupta, Deepak Kumar

Article Type: Research Article

Abstract: A fuzzy autopilot algorithm for maneuvering of surface ships is proposed and its performance studied. A mathematical model for nonlinear maneuvering of cargo ships has been used in conjunction with the proposed fuzzy autopilot. The autopilot works with two error measures that are inputs, error in heading angle and the offset error from the desired path, and has the command rudder angle as the output. Input variable fuzzification, fuzzy associative memory rules and output set defuzzification schemes using Mamdani minimum inference method are described. The proposed control scheme has been verified for a variety of straight line and curved trajectories …using a nonlinear maneuvering model of Mariner class vessel. Show more

Keywords: Autopilot, automatic control, nonlinear, maneuvering, ship, fuzzy control, fuzzy rules

DOI: 10.3233/ISP-2012-0075

Citation: International Shipbuilding Progress, vol. 58, no. 4, pp. 191-218, 2011

Authors: Mosaad, M.A. | Gaafary, M.M. | El-Kilani, H.S. | Amin, I.A.

Article Type: Research Article

Abstract: Power prediction for WIG crafts is challenging. This is due to the lack of information about its performance data, and hence, there is no simple method for power prediction yet available that can be used in the preliminary design stage. In this paper, a method to predict the required power for WIG craft is presented. The authors assume that WIG craft is a prismatic planing hull facilitated with wings and longitudinal stabilizer. The hydrodynamic and aerodynamic characteristics which describe the pitching moment, lift, drag, and different centers of each force are represented in a developed mathematical model. An iterative computer …program is structured. The output of this proposed method gives the logic and acceptable performance of the WIG craft compared to the related planing hull. An illustrative example is included to determine the required horsepower, running trim and take-off speed. Show more

Keywords: Power prediction, aero and hydrodynamic of WIG crafts

DOI: 10.3233/ISP-2012-0076

Citation: International Shipbuilding Progress, vol. 58, no. 4, pp. 219-238, 2011

Article Type: Other

Citation: International Shipbuilding Progress, vol. 58, no. 4, pp. 239-240, 2011