483 research outputs found
Robo-Yacht: a human behaviour-based tool to predict the performances of yacht-crew systems
No full textMany numerical tools are available in the yacht design domain to predict yacht performances. These are based on experimental data and well-established numerical techniques. However, being competitive sailing an uncertainty-rich discipline, there is also a need to assess the performances of a yacht’s crew. This is indeed the main area for performance gains. The present study aims at predicting the performances of yacht-crew systems, by including numerical models for human behaviour within those referred to the yacht dynamics.
In particular, the problem of decision-making under weather uncertainty is formulated in terms of a game of chance having nature as a second player and involving risk. Within this context, it is shown that decisionmaking models often used in management sciences can be advantageously used. This approach has led to the development of a sailing simulator referred to as ‘Robo-Yacht’, based on the International America’s Cup Class. A case study is investigated that involves three strategical alternatives and four possible weather scenarios: gains and losses are assessed through the simulator and a formula to express expected payoffs is derived. When different attitudes towards risk (neutral, risk-averse and risk-taking) are expressed as different utility functions,
it is shown that sailors’ choices can be conveniently modeled based on a maximization of expected utility. The ‘automatic crew’ can actually make decisions that appear to be consistent with widely accepted principles of race strategy. A risk function is also derived in order to take into account opponents’ choices and, where necessary, modify the strategic plan accordingly
New analytical metodologies for environmental control of toxic heavy metal pollution in natural waters.
No full textInfluence of water on the electroanalytical behaviour of (K,Na)HSO4 eutectic melt. Characterization of Hg32+.
No full textErrata corrige, 69 (1979) Author Index, p. 3
Determinazione di metalli pesanti in acqua di mare mediante voltammetria di ridissoluzione anodica.
No full textAnodic stripping voltammetric (ASV) determination of Zn, Cd, Pb, and Cu in seawater of the Lagoon of Venice.
No full text
Lifting line method for modelling covering and blanketing effects for yacht fleet race simulation
No full textAn approach is presented that can be used to enhance the realism of yacht fleet race simulations. The wake of an upwind sailing yacht is represented as a single heeled horseshoe vortex (and image) system. At each time step changes in vortex strength are convected into the wake as a pair of vortex line elements. These subsequently move in accordance with the local wind, self-induced velocity and velocity induced by the presence of the wakes of other yachts. An empirical based decay factor is used to eventually remove the far wake. A synthesis of sail yacht wake representations based on detailed 3D Reynolds Averaged Navier-Stokes (RANS) Computational Fluid Dynamics (CFD) calculations with wind tunnel test results are used to capture the initial strength of the combined main-jib vortex system and its vertical height. These were based on a typical upwind sail arrangement for a range of heel angles and in-line calculations for a pair of yachts separated by three boat lengths. This paper details the basis of the validated CFD results for a yacht at heel and the analysis of the CFD results to provide an approximate single line vortex method for the yacht. The developed algorithm will eventually run within the Robo-Race which is a real-time yacht race strategy analysis tool based on MATLAB®-Simulink® developed at the University of Southampton
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