1,721,002 research outputs found
INVESTIGATION ON MODEL-SHIP CORRELATION AND ON POWER PREDICTION FOR HIGH SPEED MULTI-HULLED VESSELS
Crete (Greece
Risposte in Mare Regolare di uno Stowage Tanker, Libero ed Ancorato
Ricerca sperimentale ed analisi dei risultati di prove di mooring per Fincantier
Multi-objective optimisation of a semi-planing hull using CFD RANSE simulations with low number of cells
An integrated use of a CFD software with an algorithm for multi-objective optimization is proposed in this paper. Currently, optimisations regarding hydrodynamic performance for a given ship or marine vehicle design (eg. choice of best shape for the minimization of wave resistance) can be carried out interfacing multiobjective algorithms with parametric 3D modelers and suitable hydrodynamic solvers. Having to manipulate a great number of alternatives, the requirement for the computing chain is to rely on fast and tested methodologies especially for the flow solvers. The use of RANS viscous CFD simulations offers more complete and detailed information to evaluate the resistance and the flow around ships hulls and is now well established. These methods, however generally require to represent the flow domain by a high number of cells with consequent substantial increase of hardware and computing time requirements. A research has been carried out to define and standardize operating modes to carry out viscous simulations with a number of cells as low as possible. It has allowed to obtain adequate results within a reasonable short time and without the necessity of requiring high computing resources. In this way it is possible to achieve adequate RANS simulations in a short time so as to make them competitive as far as computational costs with panel methods also in optimization problems, especially in the evaluation phase of many different design alternatives. The optimization of a hard-chine semi-planing hull, based on the reduction of the total resistance at two different speeds through the integration of software optimisation with the RANS simulations with low number of cells has been performed and is presented and discussed. The results obtained are validated by experimental tests in towing tank
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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