International Shipbuilding Progress - Volume 61, issue 3-4

Authors: Dash, Anil Kumar | Nagarajan, Vishwanath

Article Type: Research Article

Abstract: The uncertainty of various coefficients of 8 degrees of freedom (DoF) twin-propeller twin-rudder (TPTR) maneuvering mathematical model has been determined. A stochastic response surface method (SRSM) is developed for propagating these uncertainties to the full scale simulations of ship maneuvers. The proposed SRSM uses Hermite polynomial chaos (PC) expansion of standard random variables (SRVs) for analysis. Here SRVs are Gaussian variables. The SRSM approximates all model inputs and outputs as a function of SRVs and develops an approximate surrogate model for a specific output. The SRSM treats any deterministic model as a “black-box”. SRSM requires less computational time as compared …to standard Monte Carlo Simulation (MCS) method. Full scale simulations of a TPTR model installed with gas turbine propulsion at a cruising speed of 30 knots have been carried out. There are 60 uncertain inputs and 14 uncertain outputs present in the model. A linear sensitivity study has been carried out to select a set of most sensitive inputs for each one of the different outputs. Only the sensitive inputs are considered for computing the output distribution. Asymmetric behavior and uncertainty in the characteristics of twin-propeller twin-rudder system are significant. Uncertainty for overshoot angle, advance, tactical diameter, propeller revolution and thrust, engine torque, rudder normal force and torque are presented. Show more

Keywords: Uncertainty propagation, stochastic response surface method, Monte Carlo simulation, sensitivity analysis, twin-propeller twin-rudder asymmetry

DOI: 10.3233/ISP-140110

Citation: International Shipbuilding Progress, vol. 61, no. 3-4, pp. 129-161, 2014

Authors: Jiang, Wen-ying | Lin, Yan | Chen, Ming | Yu, Yan-yun

Article Type: Research Article

Abstract: An optimization approach for the problem of the ship pipe route design (SPRD) is presented in this paper, which is based on the ant colony optimization (ACO) algorithm and the genetic algorithm (GA). The main goal of SPRD problem is to design an appropriate pipe route to connect the starting point and end point under the various kinds of constraints. Due to the large layout space, the complex construction in layout space and the great number of pipelines, SPRD becomes a very difficult task. An ACO–GA algorithm is proposed to solve the SPRD problem. Genetic operators including crossover operation and …mutation operation in GA are embedded in the computing process of ACO to improve the computing performance of the proposed algorithm. Based on the ACO–GA, an algorithm is proposed to solve the problem of the multiple pipes and the branch pipe routing. The Simulation results demonstrate the feasibility and effectiveness of the proposed algorithm. Show more

Keywords: Ship pipe route design (SPRD), ACO–GA, multiple pipes routing, branch pipe routing, ACO, GA

DOI: 10.3233/ISP-140111

Citation: International Shipbuilding Progress, vol. 61, no. 3-4, pp. 163-183, 2014

Authors: Cai, Wenkui | Konovessis, Dimitris | Vassalos, Dracos

Article Type: Research Article

Abstract: Learning from the past has been recognised as an effective means to manage future challenges. This is particularly true for ship safety management in the maritime industry as the records of historical safety-related failures are generally accompanied by the losses of human lives, damage to the environment and the ships. However, the current “learning” practice is not rationalised to facilitate effective safety management both from design and operational points of view. By proposing a unique approach of “learning from the past”, this paper elaborates on a formal methodology towards ship safety management so that future risk control decisions can be …made in an objective, transparent, and well-informed manner. Show more

Keywords: Ship safety management, risk assessment, learning from accidents, data mining, Bayesian networks

DOI: 10.3233/ISP-140112

Citation: International Shipbuilding Progress, vol. 61, no. 3-4, pp. 185-201, 2014

Authors: Naaijen, Peter | Trulsen, Karsten | Blondel-Couprie, Elise

Article Type: Research Article

Abstract: We discuss the spatio-temporal domain, here referred to as the predictable zone, in which waves can be predicted deterministically based on an observation in a limited spatial or temporal domain. A key issue is whether the group or phase speed of the observed waves governs the extent of the predictable zone. We have addressed this issue again using linear wave theory on both computer-generated synthetic wave fields and laboratory experimental observations. We find that the group speed adequately indicates the predictable zone for forecasting horizons relevant for offshore and maritime applications.

Keywords: Wave prediction, deterministic, phase resolved

DOI: 10.3233/ISP-140113

Citation: International Shipbuilding Progress, vol. 61, no. 3-4, pp. 203-223, 2014

Article Type: Other

Citation: International Shipbuilding Progress, vol. 61, no. 3-4, pp. 225-226, 2014