An All-Round Design-to-Simulation Approach of a New Z-Drive Escort Tug Class

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Massimo Figari ◽  
Luca Martinelli ◽  
Benedetto Piaggio ◽  
Lucia Enoizi ◽  
Michele Viviani ◽  
...  
Keyword(s):  
High Speed ◽  
Methodological Approach ◽  
Simulation Models ◽  
Stability Margins ◽  
Main Research ◽  
Research Areas ◽  
Damage Stability ◽  
Hull Design ◽  
Computational Fluid Dynamics Cfd

Abstract An industrial-academic collaboration between Rosetti Marino shipyard and University of Genoa presided over a deep theoretical and experimental insight into the maneuvering performances of a new escort tug family. The presented z-drive azimuthal stern drive class is characterized by high intact/damage stability margins, good maneuvering capability, and stable behavior during escort indirect assistance. The project addresses three main research areas: hydrodynamic design of the hull with escort capability, simulation of the escort capabilities in different operational scenario, and development of control logics that will allow autonomous or unmanned operations. The tug design concept is supported by a customized simulation tool that enables the evaluation of the free-sailing and towing maneuvering characteristics for Azimuth Stern Drive (ASD) tugs at high–speed (Escort) and low speed (Harbor Assistance) in a real-time environment. The paper describes the methodological approach adopted for the design and maneuvering characterization of such a class, across some preliminary results. Computational fluid dynamics (CFD) calculations and towing tank tests have been performed onto a prototype tug hull in order to assess the hull design and to infer simulation models able to describe the behavior of a family of vessels. In particular, the propulsion and maneuverability aspects in escort operations are deeply investigated.

All Around Approach for the Design of a New Escort Tug Family

2018 ◽  
Author(s):  
Massimo Figari ◽  
Luca Martinelli ◽  
Michele Viviani ◽  
Diego Villa ◽  
Lucia Enoizi ◽  
...  
Keyword(s):  
Methodological Approach ◽  
Simulation Models ◽  
Scenario Development ◽  
Academic Collaboration ◽  
Stability Margins ◽  
Towing Tank ◽  
Main Research ◽  
Research Areas ◽  
Damage Stability ◽  
Hull Design

The aim of the paper is to describe an industrial-academic collaboration whose main goal is the design of a new escort tug family characterized by high intact/damage stability margins, good maneuvering capability and stable behavior during escort indirect assistance. The project addresses three main research areas: hydrodynamic design of the hull with escort capability, simulation of the escort capabilities in different operational scenario, development of control logics that will allow autonomous or unmanned operations. The paper describes the methodological approach adopted for the design and will show some preliminary results. The results refer to the first part of the project. CFD calculations and towing tank tests have been performed onto a prototype tug hull in order to assess the hull design and to infer simulation models able to describe the behavior of a family of vessels. In particular, the propulsion and maneuverability aspects in escort operations are deeply investigated. Results of the project will form the bases for the conceptual application to a remotely controlled or autonomous escort tug.

scholarly journals The Scientific Landscape of November 23rd, 1980 Irpinia-Basilicata Earthquake: Taking Stock of (Almost) 40 Years of Studies

Geosciences ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 482
Author(s):  
Fabrizio Terenzio Gizzi ◽  
Maria Rosaria Potenza
Keyword(s):  
Web Of Science ◽  
Southern Italy ◽  
Methodological Approach ◽  
Temporal Trends ◽  
International Studies ◽  
Main Research ◽  
Italian Studies ◽  
Research Areas ◽  
Scientific Outputs ◽  
Natural Laboratory

The November 23rd, 1980 Irpinia-Basilicata (Southern Italy) earthquake is one of the strongest earthquakes ever occurred in Italy. The earthquake was a natural laboratory for the scientific community, which was engaged highly and promptly in investigating the event, thus publishing a flood of papers in different research areas over time. Just these research outputs are the focus of the article, which examines, with a tailored methodological approach, the international and national (Italian) studies started and advanced since the occurrence of the earthquake. First, we built and analyzed statistically two bibliographic databanks regarding the earthquake studies: (a) the international version of IRpinia Bibliographic databASE (IR_BASE_ENG), selecting and standardizing the pertinent scientific documents extracted from Scopus, Web of Science, and other databases and (b) the national version of the database (IR_BASE_IT) using the Google Scholar search engine to search for the most relevant papers in Italian. Second, IR_BASE_ENG was analyzed in a bibliometric perspective through the data mining VOSviewer software (Waltman et al., 2010) that builds co-occurrence term maps useful in perspective of investigating the wide-ranging studies on the earthquake. Third, taking a cue from this network analysis, we recognized the main research topics and performed a minireview of the related international studies, integrating in it a quick reference to the literature in Italian. Finally, we associated the scientific outputs to each cluster/topic, also performing the frequency analysis of the published documents for each subject, thus gaining information on the temporal trends of studies and getting a more exhaustive evidence of the scientific landscape on the earthquake over the last 40 years.

scholarly journals Experimental Rotordynamic Characterization of Annular Seals: Facility and Methodology

1998 ◽  
Author(s):  
J. Mark Darden ◽  
Eric M. Earhart ◽  
George T. Flowers
Keyword(s):  
High Speed ◽  
Quality Data ◽  
Test Rig ◽  
Stability Margins ◽  
Rotordynamic Coefficients ◽  
Annular Seal ◽  
Theoretical Predictions ◽  
High Reynolds ◽  
Annular Seals

Annular seals are known to enhance rotordynamic stability margins and minimize vibration response levels in high-speed rotating machinery. Theoretical predictions for the rotordynamic characteristics of annular seals exist but additional experimental data is needed to properly anchor these results. NASA’s Marshall Space Flight Center (MSFC) has developed an annular seal test rig and facility to experimentally characterize axially-fed annular seals. The objective of MSFC’s annular seal test rig is to obtain the rotordynamic coefficients (direct and cross-coupled stiffness, damping, and added mass) for a variety of high Reynolds number annular seals. The MSFC test rig supports centered-seal testing with inlet pressures up to 138 bars (2000 psi) and flow rates of over 946 liters per minute (250 gpm). The rig’s shaft is powered by a 186 kilowatt (250 horsepower) steam turbine capable of rotational speeds of over 20,000 revolutions per minute (rpm). A description of the identification process used to obtain rotordynamic coefficients is given as well as procedures for ensuring quality data. Experimental results for a smooth annular seal with an L/D = 0.5 is presented. Excellent agreement between experimental and theoretical results is obtained.

Experimental Rotordynamic Characterization of Annular Seals: Facility and Methodology

1999 ◽  
Vol 121 (2) ◽  
pp. 349-354 ◽  
Author(s):  
J. M. Darden ◽  
E. M. Earhart ◽  
G. T. Flowers
Keyword(s):  
High Speed ◽  
Quality Data ◽  
Test Rig ◽  
Stability Margins ◽  
Rotordynamic Coefficients ◽  
Annular Seal ◽  
Theoretical Predictions ◽  
High Reynolds ◽  
Annular Seals

Annular seals are known to enhance rotordynamic stability margins and minimize vibration response levels in high-speed rotating machinery. Theoretical predictions for the rotordynamic characteristics of annular seals exist but additional experimental data is needed to properly anchor these results. NASA’s Marshall Space Flight Center (MSFC) has developed an annular seal test rig and facility to experimentally characterize axially fed annular seals. The objective of MSFC’s annular seal test rig is to obtain the rotordynamic coefficients (direct and cross-coupled stiffness, damping, and added mass) for a variety of high Reynolds number annular seals. The MSFC test rig supports centered-seal testing with inlet pressures up to 138 bars (2000 psi) and flow rates of over 946 liters per minute (250 gpm). The rig’s shaft is powered by a 186 kilowatt (250 horsepower) steam turbine capable of rotational speeds of over 20,000 revolutions per minute (rpm). A description of the identification process used to obtain rotordynamic coefficients is given as well as procedures for ensuring quality data. Experimental results for a smooth annular seal with an L/D =0.5 is presented. Excellent agreement between experimental and theoretical results is obtained.

#ConnectedYouthBrazil Research: Emerging Literacies in a Hyperconnected Society

2016 ◽  
pp. 171-191
Author(s):  
Brasilina Passarelli ◽  
Fabiana Grieco Cabral de Mello Vetritti
Keyword(s):  
Social Networks ◽  
Methodological Approach ◽  
Digital Age ◽  
Contemporary Society ◽  
Main Research ◽  
Social Agent ◽  
Research Areas ◽  
Youth Behavior ◽  
Multiple Dimensions ◽  
Depth Interviews

A new logic emerged in the hyperconnected contemporary society, contributing to a new kind of social agent. The emergence of social networks evolved to a diverse agents' profile, especially among the connected youth. To understand better this context a study was conducted focusing the opportunities, changes and trends of Brazilian connected youth behavior in the digital age, considering four research areas: social attitudes, education, entrepreneurship and activism. Entitled #ConnectedYouthBrazil, the research is complex and innovative in multiple dimensions with a mix of extensive quantitative survey and qualitative methodological approach, which included Internet monitoring (E-Meter), in-depth interviews and focus groups. The main research results presented in this chapter can inspire further discussion on the connected youth.

Advanced Machining Processes for CFRP

2014 ◽  
Vol 1018 ◽  
pp. 67-74 ◽  
Author(s):  
Iris Rieck ◽  
Eckhart Uhlmann
Keyword(s):  
High Speed ◽  
Fiber Reinforced ◽  
Machining Processes ◽  
Main Research ◽  
High Speed Cutting ◽  
Reinforced Plastics ◽  
Research Areas ◽  
University Of Berlin ◽  
Advanced Machining ◽  
Fiber Reinforced Plastics

The processing of fiber reinforced plastics is one of the main research areas at the Institute for Machine Tool and Factory Management of the Technical University of Berlin. In this process new tool concepts and innovative process strategies are developed, tested and prepared for the industrial application. This report presents the latest research results in the field of High-Speed-Cutting of fiber-reinforced plastics.

Social exchange processes, health behaviour, and health behaviour change

2008 ◽  
Vol 16 (3) ◽  
pp. 131-134
Author(s):  
Urte Scholz ◽  
Rainer Hornung
Keyword(s):  
Social Exchange ◽  
Health Behaviour ◽  
Psychological Research ◽  
Smoking Behaviour ◽  
Self Report ◽  
Long Term Effects ◽  
Main Research ◽  
Research Areas ◽  
Exchange Processes ◽  
Multi Method Approach

Abstract. The main research areas of the Social and Health Psychology group at the Department of Psychology at the University of Zurich, Switzerland, are introduced. Exemplarily, three currently ongoing projects are described. The project ”Dyadic exchange processes in couples facing dementia” examines social exchanges in couples with the husband suffering from dementia and is based on Equity Theory. This project applies a multi-method approach by combining self-report with observational data. The ”Swiss Tobacco Monitoring System” (TMS) is a representative survey on smoking behaviour in Switzerland. Besides its survey character, the Swiss TMS also allows for testing psychological research questions on smoking with a representative sample. The project, ”Theory-based planning interventions for changing nutrition behaviour in overweight individuals”, elaborates on the concept of planning. More specifically, it is tested whether there is a critical amount of repetitions of a planning intervention (e.g., three or nine times) in order to ensure long-term effects.

Borders, Conflicts and Bargaining in Federations and Communities of Governments

2009 ◽  
pp. 83-99
Author(s):  
A. Libman
Keyword(s):  
Economic Policy ◽  
Public Authority ◽  
Modern World ◽  
Main Research ◽  
Research Areas ◽  
Nation States ◽  
Distribution Of Power

Economic policy in the modern world can be treated as an outcome of interaction of multiple territorial centers of public authority: nation-states, subnational and supranational jurisdictions. In the last decades economics has increased its attention to the factors which influence the distribution of power among jurisdictions. The paper surveys two main research areas in this literature: economics of conflicts and theory of endogenous decentralization. It discusses the basic models of both approaches and their modifications applied in the literature as well as factors of conflict formation and bargaining over devolution.

Yaw Galloping of a TLWP Platform Under High Speed Currents by Analytical Methods and its Comparison With Experimental Results

2017 ◽  
Author(s):  
Francisco Lamas ◽  
Miguel A. M. Ramirez ◽  
Antonio Carlos Fernandes
Keyword(s):  
High Speed ◽  
Production Systems ◽  
Experimental Tests ◽  
Experimental Results ◽  
Analytical Methodology ◽  
New Approach ◽  
Laboratory Facilities ◽  
Polynomial Curve ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses

Flow Induced Motions are always an important subject during both design and operational phases of an offshore platform life. These motions could significantly affect the performance of the platform, including its mooring and oil production systems. These kind of analyses are performed using basically two different approaches: experimental tests with reduced models and, more recently, with Computational Fluid Dynamics (CFD) dynamic analysis. The main objective of this work is to present a new approach, based on an analytical methodology using static CFD analyses to estimate the response on yaw motions of a Tension Leg Wellhead Platform on one of the several types of motions that can be classified as flow-induced motions, known as galloping. The first step is to review the equations that govern the yaw motions of an ocean platform when subjected to currents from different angles of attack. The yaw moment coefficients will be obtained using CFD steady-state analysis, on which the yaw moments will be calculated for several angles of attack, placed around the central angle where the analysis is being carried out. Having the force coefficients plotted against the angle values, we can adjust a polynomial curve around each analysis point in order to evaluate the amplitude of the yaw motion using a limit cycle approach. Other properties of the system which are flow-dependent, such as damping and added mass, will also be estimated using CFD. The last part of this work consists in comparing the analytical results with experimental results obtained at the LOC/COPPE-UFRJ laboratory facilities.

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