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2021 ◽  
Vol 10 (1) ◽  
pp. 16
Author(s):  
Ermina Begovic ◽  
Carlo Bertorello ◽  
Fabio De Luca ◽  
Barbara Rinauro

This paper reviews a state-of-the-art zero emission propulsion system for a battery-powered small craft. The main aspects considered are the available propulsion systems, energy storage, and dock battery charging. This underlying activity is part of the KISS project, a research and development program in the frame of the EU-funded “Piano Operativo Regionale CALABRIA FESR-FSE 2014–2020 ASSE I–PROMOZIONEDELLA RICERCA E DELL’INNOVAZIONE”, which is aimed at designing and building a physical prototype. Its hull form is based on previous research conducted by the authors, and the powering performances were preliminarily predicted by CFD simulation. The KISS project represents a successful example of an electric small craft with performances and a mission profile comparable to competitors with conventional propulsion. Such a target has been achieved by a concurrent design that considers the hull form, engine, propulsion system, and energy storage onboard. Safety issues and the regulatory frame are also highlighted.


2021 ◽  
Vol 163 (A3) ◽  
Author(s):  
Jean-Baptiste Souppez

Timber construction has recently seen a significant regain of interest across a range of industries, owing to contemporary concerns for sustainability. In the marine industry, historic principles of traditional wooden boatbuilding remain present, with empirical rules still common practice, as is the case for scarf joints. Moreover, laminated wood is made more attractive and efficient thanks to modern adhesives. However, with the progress made in structural analysis, these assemblies can now be refined based on scientifically informed evidence. This paper employs destructive testing to tackle two distinct cases. On the one hand, the strength of plain scarf joints as a function of their slope is evaluated. On the other hand, the effectiveness of a range of adhesives is ascertained for the purpose of laminated manufacturing. The results are compared to both solid wood and the mechanical properties assumed by modern scantling regulations, revealing significant differences. The novel research findings provide a better understanding of these fundamental timber construction principles, supporting designers and builders alike in making informed choices while promoting safer regulatory compliance and enabling the future development of structural small craft standards. Applications beyond the structural design of wooden boats are also anticipated, for instance in sustainable buildings and architecture.


2021 ◽  
Author(s):  
Arman Bhardwaj ◽  
M. Javad Javaherian ◽  
Nicholas Husser

Slamming is a critical loading condition that governs design of high-speed small craft. Due to sparse pressure measurements in previously conducted experimental studies and uncertainties in numerical simulations, a combined study to fully understand the three-dimensional fluid-dynamics effects on the bottom of a wedge is presented herein. The focus of this paper is on a comparison of experiments and simulations on the water-entry of a rigid wedge that represents a transverse wedge cross section of a Generic Prismatic Planing Hull (GPPH). The results show that the simulations are in very good agreement with the experiments and that these 3D effects can accurately be modeled.


2021 ◽  
Vol 35 (3) ◽  
pp. 676-681
Author(s):  
John B. Alexander

This self-published book is clearly the product of a frustrated researcher. The subtitle alone provides an accurate insight into Cox’s thinking. That said, anyone who has been around these fields for any length of time can share a sense of frustration. Listening to any number self-anointed experts, and even charlatans, who populate the fields of the paranormal, can be exasperating. Yes, tall tales abound.  Unfortunately, there are no lower limits to crazy that will not attract a following. Such is the nature of studying unexplained phenomena.             The publication does not appear to have been professionally edited, as one finds both grammatical and contextual errors. Cox contracted with a company called Outskirts Press; one that specializes in physically printing self-published books. In checking with them, I found they do offer an editing service. The author would have been better served to have paid for that option, as there are many incomplete sentences and other grammatical errors. As an established author, I believe attempting to edit your own material is fraught with danger. That is the position I believe most frequently published and serious authors would agree with.             Mechanically speaking, The Fall of the Ufology appears to be designed for an e-publication, as opposed to a print format. That is because there are many Internet sites that are listed and that I suspect can be directly accessed in electronically published form. The contextual format changes significantly throughout the book. Some of it is straight nonfiction statements of fact, but that is often followed by side commentary as if one were attending a social gathering.             While the title implies the singular topic is UFOs, it digresses into many other areas. He takes significant liberties in defining, or redefining, terms that have been around for many years, even centuries. Seemingly, Cox does view himself as the arbiter of acceptability of terms. As an example, he proffers “Anomalogy” as a new term which he defines “as a person who studies anomalies,” as opposed to parapsychology or ufology. In many ways, what Cox puts forth many of us would view as a blinding flash of the obvious. The notion of the interrelationship between various fields in the study of phenomena has been addressed for decades. Several authors, including Jacques Valle and myself, have written extensively on this matter.             On a hypocritical note, Cox simultaneously admonishes Ufologists who present outlandish opinions at conferences, and then destroys his own credibility by accepting extreme conspiracy theories. While addressing his own UAP (unidentified aerial phenomena) sightings, he states that he believes the craft as being of man-made origin. That, even though he witnessed events that would be beyond our currently known technical capabilities. Specifically, on page 32 he states, “I believe now that somehow we on earth have been given this technology from ‘Outside Intelligence.’” Here, I am admittedly biased, but have explicitly eliminated that possibility in my own UFO writings. The notion that the US government has reverse-engineered a crashed UFO is not new. But as I have pointed out, if such technology existed, making small craft that flit about would be trivial compared to the fundamental understanding of an entirely new energy source. Such a capability would undeniably alter our strategic interests and geopolitical landscape forever.


2021 ◽  
Author(s):  
Pierre Aristaghes ◽  
David Compte

Abstract As part of the Monaco offshore urban extension project, Bouygues TP is in charge of design & build a maritime infrastructure as the first step of the six-hectare expansion of the city into the sea. This maritime infrastructure consists of a fill enclosed by a band of trapezoid concrete caissons and will serve as base for construction of the new residential area. The paper focuses on some of the problems which had to be solved: optimization of promenade level and wave absorbing chambers in conjunction with minimal reflection and safety related to overtopping, accounting for sea level rise and correlation between extreme waves and water levels. caissons and rubble mound foundation stability related to waves and seism, including extra seismic forces due to buildings considering the high reclamation height and the immediate proximity of building foundations. the way in which caissons representing nearly 80,000 m3 of concrete can be built in a floating and continuous manner via a caisson box (or "caissonnier" in French), within a particularly short time frame presence of a small craft harbor with shops along the quays, whose location was fixed for urbanistic reasons, which requested optimizations in detail of anti-overtopping devices as much as possible integrated in the urban context, need to convert a breakwater caisson into a low crested swimming pool caisson, with plexiglas windows exposed to wave slamming from outside, but also from inside due to overtopping impacts over the swimming pool basin. Ecodesign has been closely associated with hydrodynamic and coastal engineering, based on estimation of wave pressures and induced velocities in the different possible locations (chambers, walls, structures toes …). The eco-friendly development strategy is based on the wide-scale deployment of a range of 11 solutions which will be described (potential for caissons to be colonized, nursery function development, etc…). Moreover, posidonia transplantation has been done via concrete open boxes, whose stability under storm waves has requested CFD calculations to model local velocities and optimize their shape.


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