International Shipbuilding Progress - Volume 69, issue 1

Authors: Wellens, Peter R.

Article Type: Editorial

DOI: 10.3233/ISP-229000

Citation: International Shipbuilding Progress, vol. 69, no. 1, pp. 1-1, 2022

Authors: Oud, Guido | Toxopeus, Serge

Article Type: Research Article

Abstract: Hydrodynamic loads acting on a ship can nowadays be reliably obtained from Computational Fluid Dynamics (CFD) techniques. In particular for the determination of the hydrodynamic coefficients of a mathematical manoeuvring model, the forces and moments on a ship sailing at a drift angle or with a yaw rate can be computed efficiently with CFD. While computations with a drift angle are relatively straightforward, computations involving a yaw rate present a challenge. This challenge consists in how to deal with the grid, the setup and the ship encountering its own wake when rotating. A solution based on a single grid setup …with consistent boundary conditions and utilising a body force wake damping zone to remedy this challenge is proposed in this paper, leading to an effective, fast, and accurate method to compute hydrodynamic loads of a ship in steady yaw manoeuvres. Show more

Keywords: Manoeuvring, CFD, yaw, rotational motion, wake encounter, wake damping, body force model

DOI: 10.3233/ISP-220001

Citation: International Shipbuilding Progress, vol. 69, no. 1, pp. 3-24, 2022

Authors: Cheemakurthy, Harsha | Garme, Karl

Article Type: Research Article

Abstract: Background: Among the challenges for implementation of Waterborne public transportation (WPT) are the difficulties in procuring efficient ferries tailored towards local requirements. Fundamental questions on the ferry’s environmental impact, speed and procurement costs linger in the public transport (PTP) mind. Objective: In this paper, a methodology for adopting a platform architecture for ferries is illustrated by a modular design approach. Methods: For this, WPT operational profiles are categorized by three route types in a structure for operational requirements including sustainability performance. Generic parameters for size and speed of WPT ferries are defined. Using these parameters as …a skeletal structure, a modular commuter ferry concept is proposed as a set of basic modules. As a combination of these functionally independent modules, a ferry can be tailored to fit the operational requirements. Results: The paper proposes standard sizes for waterborne commuter craft and shows that ferries are compatible with land-based public transport in terms of energy efficiency and speed. Suitable speed ranges for mono hulls and catamarans are investigated and the idea of modular design for rational procurement is explored and illustrated for the three type routes. Conclusions: The proposed concepts can make WPT more attractive for PTPs as a sustainable option to complement the existing network. Show more

Keywords: Modular design, Waterborne public transportation, commuter ferry, product family, ship design, Waterborne urban mobility, Function Structure Heuristics

DOI: 10.3233/ISP-210016

Citation: International Shipbuilding Progress, vol. 69, no. 1, pp. 25-59, 2022

Authors: Hengelmolen, Vera | Wellens, Peter R.

Article Type: Research Article

Abstract: The added resistance is a resistance component that is not yet satisfactorily predicted, although its accurate estimation is crucial – both from an environmental and economic point of view – from the design stage of a ship until its operation. One of the possible sources of overprediction is the occurrence of bow wave breaking. The first aim of this paper is to study the effect of bow wave breaking on added resistance by combining visual observations with resistance tests. On the other hand, as the bow region of a ship appears to be the most dominant contributor to added resistance, this paper …introduces a dynamic waterline detection method involving stereo vision. This experimental method is applied to reach the second aim of this paper, which is to stress the importance of the relative wave elevation in the bow region of the ship. By placing stereo rigs inside the hull of a semi-transparent ship, the waterline at each momnent in time can be tracked using an edge detection algorithm. By performing resistance tests on the Delft Systematic Deadrise Series ship model no. 523, the added resistance is observed to be proportional to the relative wave height squared. The data of the experiment and the information necessary to reproduce the experiment are shared through https://doi.org/10.4121/19525852 . Show more

Keywords: Added resistance, bow wave, stereo vision, wave breaking

DOI: 10.3233/ISP-210018

Citation: International Shipbuilding Progress, vol. 69, no. 1, pp. 61-89, 2022