International Shipbuilding Progress - Volume 36, issue 405

Authors: Asfar, K.R. | Nayfeh, A.H.

Article Type: Research Article

Abstract: An experimental investigation of a proposed new type of surface marine vehicle is presented. The vehicle works above water surface so that its body does not come in contact with water, thereby eliminating viscous drag. It develops its lifting and thrust forces by the impact of special wheels with the water surface, thus creating hydrodynamic forces of lift and drag. The results indicate the feasibility of the proposed vehicle concept and identify some of the parameters that affect its performance.

DOI: 10.3233/ISP-1989-3640501

Citation: International Shipbuilding Progress, vol. 36, no. 405, pp. 5-17, 1989

Authors: Bari, A. | Chowdhury, K.H.

Article Type: Research Article

Abstract: Design models for seagoing ships are available in the existing literature but those for small inland commercial vessels are very rare. This paper presents consolidated design models, developed as well as collected and arranged for self-propelled inland cargo vessels and push towed tug barges having capacity upto 850 DWT. Instead of random generation approach the design model is static as they are developed on the basis of regression analyses of data of existing vessels but adequately suitable for computerisation and optimisation. Satisfactory consistency of the designs generated by the models and subsequent finally designed vessels in last four years establishes …good predictability of the model. Show more

DOI: 10.3233/ISP-1989-3640502

Citation: International Shipbuilding Progress, vol. 36, no. 405, pp. 19-50, 1989

Authors: Gueler, G.F.

Article Type: Research Article

Abstract: This work presents the modelling, analysis, preliminary design and build-up of a prototype of a submarine autopilot. The autopilot is designed to perform two different missions: depth-keeping near the sea surface and depth changing control. The vehicle dynamics are simulated by a non-linear model, whose coefficients are evaluated by the equivalent ship method. A solution of the control problem is obtained using optimal control techniques. The system state is estimated using the Kalman filter associated with the dynamical model compensation technique. A simplified filter was also used for real time state estimation. The prototype consists of …a microcomputer with analog-digital interfaces for input-output signals. A digital simulation of submarine manoeuvres was done and the results indicate a good performance for the autopilot, even under severe conditions. Other tests showed the accuracy of the non-linear model and the technical feasibility of the prototype. Show more

DOI: 10.3233/ISP-1989-3640503

Citation: International Shipbuilding Progress, vol. 36, no. 405, pp. 51-85, 1989

Authors: Lustgarten, G.A. | Aeberli, K.

Article Type: Research Article

DOI: 10.3233/ISP-1989-3640504

Citation: International Shipbuilding Progress, vol. 36, no. 405, pp. 87-130, 1989