Abstract
Dear readers of International Shipbuilding Progress,
The maritime industry is booming, and the ambitions are set high. There is much potential offshore. It inspires research to, in a responsible way, benefit from offshore resources ranging from deep sea mining, through renewable energy, to the blue economy (recently discussed in a seminar). New economies will require new ship designs and another way of taking care of the logistics. Ships that support these economies likely need to sail faster with lower CO2 emissions and with a higher degree of intrinsic safety. Our current issue contributes to the aforementioned ambitions featuring research about improving hydrofoils, keeping track of CO2 emissions, and predicting accelerations in wind-assisted craft that could lead to injury.
The issue contains the following contributions:
The first article, titled On enhancement of hydrofoil performance by partial cavitation by Amromin discusses benefits of cavitation, where we often talk about mitigating the adverse effects of cavitation. For hydrofoils the benefit of applying ventilated cavitation may not be as high as desired at lower forward velocities. Analysis of experimental data is performed to explain the reduced benefit.
The next article is titled Carbon intensity of ‘average’ ships written by Backalov. The Fourth IMO GHG Study report is re-analyzed for the purpose of categorizing ships with regard to carbon intensity, now and in future. The study demonstrates that if no action is taken, much of the fleet will soon be rated ‘inferior’ in terms of carbon intensity. The classification also helps to identify the worst performers, so that the conclusions of the article may serve as input to help policy makers formulate measures to improve.
Lourens and Wellens in Predicting crashes of a foiling ocean racing yacht in waves by means of a DVPP propose a Dynamic Velocity Prediction Program that can simulate hydrofoil-supported high-speed sailing with limited computational effort. The main purpose of the DVPP was to scan for situations when a crash can occur in challenging sea states with potential risk to the crew. Multiple of these situations were identified and one was analyzed further to reveal that in following waves the hydrofoil can lose lift and fall down while the free surface is going up, creating an impact. The acceleration during this event exceeded 1.5g, clearly exceeding the limiting acceleration of 0.45g at which the seatbelt in a car would engage.
The editorial board and I hope that you find this issue of interest.
All the best,
Peter Wellens
Editor-in-Chief
