International Shipbuilding Progress - Volume 70, issue 2

Authors: Wellens, Peter R.

Article Type: Editorial

DOI: 10.3233/ISP-231220

Citation: International Shipbuilding Progress, vol. 70, no. 2, pp. 65-66, 2023

Authors: Holkema, K.J. | Aalbers, C. | Wellens, P.R.

Article Type: Research Article

Abstract: In head waves, water jet impacts due to run up can occur as a result of the structural configuration of some floating structures, reducing workability. Wave attenuation near the floater may reduce the risk of water jet impacts. This paper presents a numerical study of the performance and attenuation mechanisms of various plate type fixed free surface breakwaters and their ability to prevent water jet impacts on adjacent structures. Simulations are performed in two dimensions with a numerical method based on the Navier–Stokes equations in the presence of a free surface. The breakwater models are evaluated in two irregular sea …states in terms of wave transmission, reflection and energy dissipation and by their ability to reduce water jets impacts on adjacent structures. A 60 degree inclined plate is found to induce a large wave energy reduction, little wave transmission and reflection and to experience little wave loading while effectively reducing water jet impacts. Show more

Keywords: Wave impact, jet formation, floating breakwater, plate breakwater, CFD and VOF

DOI: 10.3233/ISP-230012

Citation: International Shipbuilding Progress, vol. 70, no. 2, pp. 67-80, 2023

Authors: Doornebos, Patryk | Francis, Moreno | le Poole, Joan | Kana, Austin A.

Article Type: Research Article

Abstract: This paper explores the design and feasibility of a 200-passenger, 30- to 40-knot emission-free ferry as a potential variant of the traditionally powered Coastal Cruiser 200 ferry currently operating in the Chinese Pearl River Delta. The Pearl River Delta is one of China’s most densely urbanized regions and faces numerous social, health, and economic issues due to air pollution. In addition, globally, there are no currently-operating zero-emission ferries that, at minimum, sail at 30 knots and carry 200 passengers. To assess the feasibility of the new ferry, a two step approach was followed. First, an evaluation of efficiency improving measures, …energy carriers, and propulsion systems was performed to assess the tradeoffs and identify early design choices. Second, to quantify the most technically feasible design, a technical parametric model was developed specifically for this case study. Results showed that the ferry is technically feasible using batteries, compressed hydrogen fuel cells, or liquid hydrogen fuel cells; however, each has its distinct advantages and disadvantages which influence the potential final viability. Despite the regional focus of the case study, results are applicable to all ferries with similar design requirements. Show more

Keywords: Zero-emission ferry, feasibility study, alternative fuels, ship design, parametric modelling

DOI: 10.3233/ISP-230005

Citation: International Shipbuilding Progress, vol. 70, no. 2, pp. 81-114, 2023

Authors: Wenink, Robert | van der Eijk, Martin | Yorke-Smith, Neil | Wellens, Peter

Article Type: Research Article

Abstract: Surrogate modelling techniques such as Kriging are a popular means for cheaply emulating the response of expensive Computational Fluid Dynamics (CFD) simulations. These surrogate models are often used for exploring a parameterised design space and identifying optimal designs. Multi-fidelity Kriging extends the methodology to incorporate data of variable accuracy and costs to create a more effective surrogate. This work recognises that the grid convergence property of CFD solvers is currently an unused source of information and presents a novel method that, by leveraging the data structure implied by grid convergence, could further improve the performance of the surrogate model …and the corresponding optimisation process. Grid convergence states that the simulation solution converges to the true simulation solution as the numerical grid is refined. The proposed method is tested with realistic multi-fidelity data acquired with CFD simulations. The performance of the surrogate model is comparable to an existing method, and likely more robust. More research is needed to explore the full potential of the proposed method. Code has been made available online at https://github.com/robertwenink/MFK-Extrapolation . Show more

Keywords: Multi-fidelity, Kriging, design, Computational Fluid Dynamics, lifeboat

DOI: 10.3233/ISP-230013

Citation: International Shipbuilding Progress, vol. 70, no. 2, pp. 115-150, 2023