Development of a kayak race prediction including environmental and athlete effects

The aim of this study is to produce a simulator for sprint kayak racing which would allow the prediction of race times based on the physiological capabilities and mass of a given athlete. The simulator has been verified using established empirical data for the prediction of environmental effects and has been shown to be accurate, however verification of the physiological model is difficult to do by using general race data. An investigation into the fatigue model which has been implemented shows that further investigation is required to calibrate the simulator and produce more accurate results over a variety of distances. However, the simulator does show quite how sensitive the selection of appropriate level of effort is to the final race time for the 1000m

The use of a cap-mounted tri-axial accelerometer for measurement of distance, lap times and stroke rates in swim training

This paper will report some of the findings from a trial which recorded accelerometer data from six elite level swimmers (three female and three male, varying primary event stroke and distance) over the course of a regular 15 week training block. Measurements from a headmounted accelerometer are used to determine when the athlete is swimming, marking of turning points (and therefore distance and lap-time measurements), and is processed by frequency analysis to determine stroke-rate. Comparison with video where available, and with training plans and literature where not, have proven this method to be accurate and reliable for determining these performance metrics. The primary objective of this project was to develop a low-cost, simple and highly usable system for use in swim coaching, feedback from elite coaches has indicated that development of this could be an extremely useful addition to their training regime

Modelling of the WITT wave energy converter

The paper describes the theoretical modelling and experimental validation of a novel design of ocean wave energy converter which is comprised of a floating, moored, spherical hull containing a mechanical pendulum arrangement from which power is taken when excited by incident waves. Experimental results are shown to compare favourably with those predicted by the theory. An explicit expression is derived for the capture width of the proposed device in terms of physical and hydrodynamic parameters. This exposes the multiple resonant characteristics of the device which enable it to operate effectively over a broad range of wave periods. The subsequent efficient computations allows a numerical optimisation of the design to be performed over a large space of device parameters and model sea spectrum. The work is focussed towards producing reliable estimates for the power capacity of different sized devices deployed at the EMEC site in Scotland. Predictions compare favourably with existing wave energy converter concepts

Development of an America's Cup 45 tacking simulator

This paper describes the development of an AC45 simulator conducted as a student Master’s project at the University of Southampton. The main aim was to be able to asses and improve the tacking skills of the helm and the crew through systematic training. The physical interface of the simulator replicates the seating position of the helmsman and the main trimmer and the graphical representation provides the users with visual cues of the simulated boat, boundaries and marks for a sample race course. The theoretical model uses hydrodynamic manoeuvring coefficients based on empirical formulae and experimental data. The aerodynamic forces are pre-calculated using a full-scale RANS CFD simulation. The accuracy of the model is verified against the AC45 racing tracking data to ensure that the speed loss during a tack, experienced by the users of the simulator, is as close to reality as possible. The ultimate aim of the project was to study the potential of the simulator to assess and train the crews, improving their skill in tacking the boat effectively. This has been done by examining the performance of two groups of users over a series of practice sessions. The simulator could be potentially used for training the helmsmen of the Youth America’s Cup Red-Bull teams, which have limited budgets, training days and sailing experience compared to the professional AC sailor

Interaction fluide structure appliquée a l'analyse des voiles

National audienceSee http://hal.archives-ouvertes.fr/docs/00/59/29/60/ANNEX/r_134C13NY.pd

Design and validation of an unmanned surface vehicle simulation mode

In this paper we present a multiphysics simulation model of Halcyon, an autonomous unmanned surface vehicle (USV). The simulation model presented in this paper has been developed to rapidly progress the design, development and validation of Halcyon's autonomy management system, particularly in challenging sea conditions. Using simulation for this purpose enables extensive testing across the full environmental operating envelope of the vessel, hence greatly reducing the need for real-world sea-trials. The simulator is comprised of a novel and comprehensive sea-surface wave environment model, a six degree of freedom nonlinear unified seakeeping and manoeuvring boat dynamics model, an actuation dynamics model, an autopilot and an interface with an autonomy management system. Results are presented that show good agreement between real-world and simulated sea-trials data

Methods for assessing the seakeeping performance of high speed displacement monohulls and catamarans

The research programme has investigated methods for assessing the seakeeping performance of high speed vessels. This has included a review and assessment of seakeeping attributes, the development of a suitable database of motion characteristics using experimental and numerical techniques and proposals for assessing the seakeeping characteristics of alternative vessels. An experimental test programme was carried out in regular head and oblique waves as well as irregular open seas on two different hull forms of fast displacement catamarans. The results of the experiments in oblique waves are extended to beam and following headings using the transfer functions from a 3D pulsating source code at headings from head to following sea in regular waves. This effectively provides a means of generating 3D transfer functions. The methodology used to compare and assess the seakeeping performance of vessels at an early design stage is discussed. The use of short crested seas as opposed to long crested is assessed and the differences compared. This leads to the use of spreading relationships to generate 3D transfer functions from the database of transfer functions in regular head waves. This allows the motion prediction method to be greatly enhanced by allowing any heading to be assessed. The proposed attributes and criteria suitable for assessing the seakeeping performance of high speed vessels are summarised

Two-dimensional numerical modelling of slamming impact loads on high-speed craft

The constant velocity impact of a flexible panel with water is simulated by using the computational fluid dynamics code Star CCM+ coupled with the finite element code ABAQUS. A detailed description of the numerical model is given, and issues with numerical stability are discussed. The influence of different structural boundary conditions in the two-dimensional model is examined. The effects of hydroelasticity on the fluid loading are discussed by comparing the results from hydroelastic and rigid body simulations. Comparisons with published experimental data show favourable agreement for the test case investigated