Ermina Begovic

University of Naples Federico II | UNINA · Department of Industrial Engineering

In the 1861, the frigate “Terribile” was the first ironclad of the emerging Italian Navy and her history is interesting for both technical point of view and historical events. In fact, as the industrial revolution unfolded in the 19th century, the age of wooden hulled sailing ships gave way to that of steam powered iron ships. Moreover, due to the...

The paper discusses the future of ship stability as a scientific and engineering discipline in view of the possibilities for making progress in the “conventional” ship stability topics by employing advanced numerical tools (such as CFD), artificial intelligence techniques (such as Machine Learning), high performance computing, increased connectivit...

The design process of motor yachts mainly relies on the experience of designers, who have confidence in the knowledge acquired from designing units with similar hull-form characteristics. However, once a new concept needs to be developed, the acquired experience on a standard platform is no longer sufficient to achieve in a short time a successful...

This work shows the performance of LincoSim, a web-based virtual towing tank enabling automated and standardized calm water computational fluid dynamics (CFD) data sampling, extending previous published applications to the case of a high-speed hull. The calculations are performed for a 1:10 scale model of a 43 ft powerboat hull form in the Froude n...

The assessment of the maneuverability of high-speed vessels is crucial during the early stages of their design. To predict the maneuvering characteristics of a vessel, the accurate assessment of hydrodynamic derivatives is necessary. Thus far, several experimental, analytical, and empirical methods have been utilized to determine such hydrodynamic...

The large and mega yachts market shows the increasing trend of “expedition capable” vessels cruising all around the globe, from Antarctica to the Arctic Circle, with the highest comfort standards. Within this frame, the accurate assessment of the seakeeping characteristics is essential for the successful design and eventually the adoption of a stab...

The prediction of the dynamics of High-Speed Craft (HSC) with prismatic hulls is commonly performed by designers using semi-empirical formulations based on Savitsky’s classic method. However, the accuracy of this prediction decreases with the presence of warp, when the deadrise of the hull change along its length, which is typical for small passeng...

The importance of comfort during transfer and stationing becomes a key performance parameter for large yacht design, on the same level as propulsive issues. Such a matter extends questions in terms of form and service demand to the motion behaviour of the unit in waves. Relevant studies refer to outdated hull forms not specific to modern large yach...

Committee Mandate: Concern for structural challenges of non-conventional, special surface vessels, including uncertainties in established design methods and modelling techniques. Particular attention shall be given to mega yachts, naval craft, offshore service vessels and work boats, which can be characterized by particular structural configuration...

Discussion Discussers’ reports and floor discussions, including the replies by the committees, are included in this Volume 3 discussion paper. Committee Mandate Concern for structural challenges of non-conventional, special surface vessels, including uncertainties in established design methods and modelling techniques. Particular attention shall b...

Excessive acceleration criterion, developed by the International Maritime Organization within the Second Generation Intact Stability Criteria, deals with lateral accelerations experienced by people onboard. Level 2 criterion considers the ship at zero speed in beam waves, neglects diffraction and gives the expressions for the Froude-Krylov roll mom...

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...

Ship safety, specifically intact stability, can be substantially improved using operational measures. To date, operational measures, such as routing, heavy-weather avoidance, tacking in storm conditions etc., relied only on the ship master’s experience and were implicitly considered in the IMO regulations and rules of classification societies under...

Ship safety, specifically intact stability, can be substantially improved using operational measures. To date, operational measures, such as routing, heavy-weather avoidance, tacking in storm conditions etc., relied only on the ship master’s experience and were implicitly considered in the IMO regulations and rules of classification societies under...

Stability has always been the main safety issue for all marine vessels, and static stability evaluation is adequate for ship service. [...]

The paper presents an approach for time-domain simulation of structure responses, along with hydromechanic and structure inertia loads and motions responses, for high-speed planing craft in waves. Hydromechanic loads and motion responses are calculated with a non-linear time-domain strip method. A pressure shape function is introduced which enables...

Surf-riding phenomenon occurs when a ship sailing in following waves is accelerated to wave celerity. In this paper, surf-riding occurrence is studied for the parent hull of the Systematic Series D by 3 degrees of freedom (DOF) CFD simulations. Simulation cases are chosen following IMO recommendations for a wavelength to ship length range and follo...

The rules and regulations inherent to the design pressures and scantlings of high-speed powercrafts are numerous, and regularly reviewed. Recently, the new ISO 12215-5:2019 made notable changes to the way high-speed crafts are analysed, including extending the acceleration experienced up to 8 g in certain circumstances. Nevertheless, despite the mu...

The International Maritime Organization (IMO) finalized the Second Generation Intact Stability Criteria (SGISC), in February 2020. They are intended to be included in Part A of the 2008 International Code on Intact Stability in the following years. The SGISC consider five modes of dynamic stability failure in waves: parametric roll, pure loss of st...

Surf-riding/broaching failure mode is one of the Second Generation Intact Stability Criteria (SGISC) dealt by IMO. The SGISC are structured with a multi-tiered approach: Level 1, Level 2 and Direct Stability Assessment (DSA). When a ship does not verify one level, the next once must be applied, or the ship design must be modified. If ship changes a...

Hull forms of high-performance sailing dinghies are very interesting for yacht designers. After a long period in which the attention has been focused on one-design boats, in recent years a few exciting restricted classes such as International Moth, International 14′, 18’ Skiff and Class A catamaran become recognized in several countries and led to...

The modelling of planing craft dynamics in waves and related fluid-structure interaction is a hard challenge due to the highly nonlinear, transient and stochastic nature of the whole process. This paper explores the prospectives of detailed experimental modelling of the local structure responses for high-speed planing craft in waves. A novel experi...

Computational fluid dynamics (CFD) modelling is a powerful tool to analyze complex hydrodynamics problems like flow around bluff bodies and their interactions including flow separation and reattachments where analytical formulas are not applicable nor reliable. Nevertheless, a relevant limitation on the systematic adoption of automated CFD workflow...

In this paper, the validation of the hybrid frequency–time domain method for the assessment of hard chine displacement hull from vertical motions is presented. Excitation and hydrodynamic coefficients in regular waves are obtained from the 3D panel method by Hydrostar® software, while coupled heave and pitch motions are calculated in the time domai...

A proper design of the mooring systems for Wave Energy Converters (WECs) requires an accurate investigation of both operating and extreme wave conditions. A careful analysis of these systems is required to design a mooring configuration that ensures station keeping, reliability, maintainability, and low costs, without affecting the WEC dynamics. In...

The Second Generation Intact Stability Criteria (SGISC) are developing since 2002 after a series of naval accidents, which clearly demonstrated that actual stability criteria are not adequate to account for significant changes in the design and operation characteristics of new commercial ships. The philosophy is a multi-level approach in which succ...

Ship accidents that entail flooding may lead to disastrous consequences which could be avoided or mitigated based on the knowledge of damaged ship dynamics. The dynamic behaviour of a damaged hull is a complex phenomenon involving the interaction of the flooded water and the ship motions. The presence of a damage opening allows water flow into and...

An extensive experimental investigation on four SWATH hull forms has been conducted in calm water and in regular waves at University of Naples Federico II. Calm water tests have been analyzed in the range of Froude number FrT from 0.1 to 0.6. For all four SWATH configurations at the speed, corresponding to FrT 0.32, the behaviour in regular waves h...

This paper is focused on the first and second level vulnerability assessment of Surf riding/Broaching and Pure Loss of Stability Criteria according to IMO second generation intact stability criteria. The calculations are performed for the semi-displacement twin-screw round-bilge hull form model D1 of the Systematic Series D. This model has hull for...

The Second Generation Intact Stability Criteria (SGISC) have been introduced after the occurrence of stability-related accidents, which clearly demonstrated that “actual” intact stability criteria were not adequate. New generation criteria are based on the physical and failure mode analysis of parametric roll, pure loss of stability, surf-riding/br...

An extensive campaign of model and full scale experimental tests and numerical computations is being undertaken within the framework of the Project “SOPHYA - Seakeeping Of Planing Hull YAchts”, co-financed by Friuli-Venezia Giulia Region in the field of joint industrial and academic research. The project is aimed at the prediction and optimization...

The paper presents a numerical roll damping assessment of the intact DTMB 5415 naval ship at zero speed. Free model motions from four experimental roll decays with initial heeling angle of 4.0, 13.5, 19.58 and 24.50 deg, performed previously at the University of Strathclyde, Glasgow, have been analysed and the one with 19.58 deg initial heeling has...

This paper considers the assessment of vertical accelerations of high speed planing craft in waves as the principal element for the risk management approach, i.e. formulation and application of operational limitations and operational guidance. Semi-empirical methods used by classification societies for vertical acceleration assessment are scrutiniz...

The study reported in this paper is focused on experimental investigation of the hull girder loads on an intact and damaged naval ship DTMB 5415 at zero speed. The experimental campaign was carried out in head and beam regular waves at the University of Strathclyde. The effect of the use of moorings in the model experimental setup was investigated...

This book aims to provide a deep look into Italian actions taken in some fields of science and high performance computing (HPC), and the Italian effort to bridge the HPC gap with respect to Europe. The Italian PON ReCaS Project is written for graduate readers and professionals in the field of high performance computing. It presents and discusses in...

The aim of the work is to evaluate the 3-dimensional pressure distribution exerted on the planing hulls by Morabito empirical method and by numerical simulations performed using the commercially available flow simulation software CD-Adapco STAR CCM+. For planing hull model, tested in towing tank by authors, Computational Fluid Dynamics (CFD) simul...

This paper reports the design considerations and the evaluation of practical lowest size limits of SWATH hull form application. Static stability requirements have been considered from the very first design steps and the strut waterplane area has been minimized while assuring necessary stability of SWATH craft. The dynamic instability has been analy...

This paper presents an experimental research for the assessment of pressure field on the bottom of a mono-hedral hard chine hull at high relative speed. Tests have been performed in rough sea for two wave lengths at Fn ranging from 0.79 to 1.46. The measured pressures have been analysed in time and in frequency domain. The pressure distribution alo...

The paper focuses on the analysis of experimental seakeeping data in irregular head sea relative to constant deadrise and warped model representative of current design trends for planing hull forms. Tests have been performed at four volumetric Froude numbers ranging from 2 to 4 in one sea state. Due to non-linear nature of high-speed craft dynamics...

This paper presents the results obtained by MArine HYdrodynamics Research Group of Department of Industrial Engineering (DII) at University of Naples regarding design and development of a zero emission craft for service in Mediterranean coastal Marine Protected Areas (MPA).

This paper presents an experimental research for the assessment of pressure field on the bottom of a mono-hedral hard chine hull at high relative speed. Tests have been performed in rough sea for two wave lengths at Fn ranging from 0.79 to 1.46. The measured pressures have been analysed in time and in frequency domain. The pressure distribution alo...

The good seakeeping characteristics of SWATH hull form are very interesting for small working craft and pleasure boats. Intrinsic limitations as the low values of weight per inch of immersion and transversal and longitudinal instability, can be acceptable and successfully managed when the mission profile does not ask for significant load variation...

This paper presents an overview of the Lecco Innovation Hub project and in particular to the Sailing Yacht Lab project a 10 m length sailing yacht which aims to be a full scale measurement device in the sailing yacht research field. A description of scientific framework, measurement capabilities as well as of the principal design, building process,...

This paper presents an assessment of the roll damping of DTMB 5415 naval ship model in both intact and two compartments symmetric damaged scenarios. An experimental assessment of roll decay is performed at zero speed at different initial heel angles at the University of Strathclyde, Glasgow. Reported experimental results are decay curves, natural f...

The accurate prediction of ship resistance in waves is nowadays of increased importance since it greatly influences ship performance regarding sustainable service speed and fuel consumption in seaways. Added resistance is considered as the longitudinal component of the second order mean force acting on a ship in waves and can be calculated from the...

Slamming pressure assessment is an important topic for shell plating and stiffener design of bow flare. In this study, the pressure distribution on the bottom plating of an high speed planning craft is evaluated through measurements of the impact pressures on scale model running in regular waves. The planing hull model, monohedral hard chine built...

One monohedral and three warped hard chine planing hull forms were designed at Department of Industrial Engineering, University of Naples. All models have the same transversal section at 0.25 L from the stern with 16.7° deadrise angle. Warped models have deadrise angle linearly varying along the hull length. In previous work the results of an exten...

The results of experimental tests relative to resistance, seakeeping and roll decay of a warped hard chine hull form, suitable for large yacht design are reported. To better investigate the effect of hard chine, a round bilge identical model has been tested. Resistance tests have been performed at FV ranging from 0.90 to 4.14, for three different L...

The results of experimental tests relative to resistance, seakeeping and roll decay of a warped hard chine hull form, suitable for large yacht design are reported. To better investigate the effect of hard chine, a round bilge identical model has been tested. Resistance tests have been performed at Fv ranging from 0.90 to 4.14, for three different L...

The paper presents the results of planing hull seakeeping tests in irregular seas. The tested model belongs to a small systematic series developed at the University of Naples; it is a prismatic hull very similar to the well-known Fridsma's models. The 16.7 degrees deadrise angle, length-to-breadth and load coefficient are representative of modern h...

This paper presents an extensive study on the experimental prediction of motions for the well-known 5415 frigate hull in intact and damaged conditions. The experimental campaign is conducted for two geosim models, 1/100 and 1/51 scale, at zero speed in head, beam and quartering seas. All experimental results for 1/51 model are presented as 1st and...

The sustainable design of small passenger vessels and large size pleasure craft indicates new trends: lower speed, reduced fuel consumption and better seakeeping in all range of velocities. Small amplitudes of roll motion are considered one of the most important comfort parameter. These trends call for reviewing some commonly used concepts and desi...

In this paper the results of experimental tests relative to resistance, seakeeping and roll decay of a warped hard chine hull form, suitable for large yacht design are reported. All tests have been carried out at University of Naples, using a scale model of 2.00 m LOA- Resistance tests are performed at FV ranging from 0.90 to 4.14, for three differ...

A multi-attribute concept design procedure, as developed at the University of Zagreb, is applied to the small craft. Specialized concept design models of several generic types, e.g. mono-hull ferry, catamaran ferry, fishing vessel, fast SAR, patrol and paramilitary craft, were developed and included into a multi-attribute design procedure. In the p...

A multi-attribute concept design procedure, as developed at the University of Zagreb, is applied to the small craft. Specialized concept design models of several generic types, e.g. mono-hull ferry, catamaran ferry, fishing vessel, fast SAR, patrol and paramilitary craft, were developed and included into a multi-attribute design procedure. In the p...

In this paper the wake wash phenomenon produced by High Speed Craft (HSC) is analysed. Briefly the hydrodynamic phenomenon of wake wash is described indicating the parameters influencing the generation of wake wash from HSC at different speed and depth. The critical conditions for typical dimensions and speed of HSC are identified. In presente...

In this paper the first field measurements of wake wash produced by High Speed Craft (HSC) operating in the Bay of Naples are presented. The fleet in service in the Bay is analysed and the main characteristics of these units are given. Their routes are monitored and three critical points, where the distance from the coast is less than 700 m, for wa...

This paper presents the results of a research program carried out on different trimaran hull forms and configurations suitable for medium size fast ferries. Resistance tests on large size scale models of the two different hull forms of main hull and outriggers, both isolated and combined in different configurations have been carried out at the towi...

The latest development of the multi-attribute concept design model of the fishing vessel is presented. A wide data base of fishing vessels made it possible to introduce reliable parameter relations in the design model. The model is aimed primarily at the Adriatic type of fishing vessels with the length of up to about 30 m. Steel, aluminium, timber...