High Performance Sailing in Olympic Classes - a Research Outlook and Proposed Directions

The purpose of this paper is to explore research opportunities in Olympic sailing classes. Olympic classes provide high-performance sailing using a diversity of equipment, with the understanding that the equipment, individual athletes, and the knowledge relating to those two factors impacts performance. Thus, the Olympic motto, “Citius, Altius, Fortius” (Latin for “Faster, Higher, Stronger”), governs everyday life for many engineers. During the last few years, Chalmers has supported a project that focuses on the possibilities and challenges for research combined with engineering knowledge in the area of sports. The initiative has generated external funding and gained great acclaim within Chalmers, among staff and students, in the Swedish sports movement, and in large companies, as well as within small and medium sized enterprises. The project focuses on five sports: swimming, equestrian events, floorball, athletics, and sailing. The contribution from this paper describes an outlook identifying eight areas containing research opportunities: sailing dynamics, how to sail in Olympic classes, fluid structure interaction, surface structures, turbulence induction on the rig, equipment in Olympic classes, and applying game theory to sailing

Purjehtijan optimaalinen positio olympialuokan jollassa

As the Laser Olympic dinghy is one of the highest level sail racing classes in the world, there is an interest in obtaining scientific facts around the tons of experience that already exist. For this reason, a numerical investigation was carried out to find the optimum heel and trim angles for upwind sailing. Flat water was assumed. Systematic Computational Fluid Dynamics (CFD) Simulations were carried out to find the optimum trim versus heel at speeds of two, three, four and five knots. During these computations the leeway was fixed for each speed. The leeway angles were estimated using the resistance results obtained from the tank tests and foil theory. A special purpose VPP was developed accepting CFD results at the given speeds as input for the hydrodynamic forces, while the aerodynamic forces were obtained using Hazen’s empirical model. The output from the program was the true wind speed required to achieve the target speed at 45 degrees true wind angle. By systematic variation of the sailor’s position the optimum heel (and the corresponding trim) was obtained at the minimum required wind speed. The reason for developing this unconventional VPP was to avoid interpolation between the speeds computed by CFD. Since the resistance/speed relation is very non-linear interpolation would have been too approximate for finding the rather flat heel/trim optima. The computational techniques and the optimum heel and trim angles of the dinghy will be reported in this thesis. In the course of the computations several interesting flow phenomena were investigated, such as the interactions between the centreboard and the rudder, and between the hull and the appendages. These by-products will be briefly reported in the Conclusions and Future Work –chapter.Olympiajolla Laser on maailman kovatasoisimpia ja kilpailluimpia purjehdusluokkia, joten on kiinnostavaa etsiä tieteellisiä faktoja olemassa olevan laajan käytännön kokemuksen ympärille. Tällaisen tieteellisen faktan tuottamiseksi tässä tutkimuksessa on ratkaistu Laser-jollan optimaaliset kallistus- ja viippauskulmat laskennallisesti. Tutkimus koskee vastatuulipurjehdusta ja olettaa aallottoman vedenpinnan. Optimaalisen kulkuasennon löytämiseksi suoritettiin systemaattinen sarja virtaussimulointeja (CFD) kahden, kolmen, neljän ja viiden solmun nopeuksissa. Näissä simuloinneissa sortokulma oli määrittetty vakioksi jokaiselle nopeudelle erikseen. Sortokulmat arvioitiin käyttämällä allaskokeiden tuloksia sekä laskemalla evien tuottama vastus ja sivuttainen voima analyyttisesti. Erityinen purjeveneen suorituskykyä arvioiva ohjelma (VPP) kehitettiin tämän tutkimuksen sisällä. Ohjelman hydrodynaamisina lähtöarvoina käytettiin CFD tuloksia määrätylle nopeudelle. Aerodynaamiset voimat ratkaistiin Hazenin empiirisestä purjeaerodynamiikka -mallista. Ohjelman tuloksena saatiin tarvittava tuulen nopeus, jotta vene purjehtii 45 asteen kulmassa tuuleen määrätyllä nopeudella. Muuttamalla veneen kulkuasentoa systemaattisesti löydettiin veneen optimaalinen kulkuasento kallistuksen ja viippauksen suhteen pisteestä, jossa vene tarvitsi vähiten tuulta saavuttaakseen määrätyn nopeuden. Erityinen käänteinen VPP kehitettiin, jotta pystyttiin välttämään interpolointi CFD-simuloinneissa ratkaistujen nopeuksien välillä. Vastuskäyrän epälineaarisuudesta johtuen nopeuksien välinen interpolointi olisi vähentänyt tutkimuksen tarkkuutta. Tutkimuksessa käytetyt laskennalliset tekniikat ja optimaaliset kallistuskulmien tulokset esitetään tässä tutkimuksessa. Simulointien yhteydessä tutkittiin monia mielenkiintoisia virtausilmiöitä, kuten kölin ja peräsimen välistä vuorovaikutusta ja vastaavasti rungon ja kölin vuorovaikutusta. Näitä sivuhavaintoja käsitellään lyhyesti työn lopussa

Performance prediction for sailing dinghies

This study describes the development of an approach for performance pr ediction for a sailing dinghy . Key modelling issues addressed include sail depowering for sailing dinghies which cannot reef; effect of crew physique on sailing performance, components of hydrodynamic and aerodynamic drag , decoupling of heel angle from heeling momen t, and the importance of yaw moment equilibrium. In order to illustrate the approaches described, a customised velocity prediction program (VPP) is developed for a Laser dinghy . Results show excellent agreement with measured data for upwind sailing , and correctly predict some phenomena observed in practice . Some discrepancies are found in downwind condition s, but it is speculated that this may be related at least in part to the sailing conditions in which the measured data was gathered. The ef fect of crew weight is studied by comparing time deltas for crews of different physique relative to a baseline 80kg sailor. R esults show relatively high sensitivity of the performance around a race course to the weight of the crew, with a 10kg change contr ibuting to time deltas of more than 60 seconds relative to the baseline sailor over a race of one hour duration at the extremes of the wind speed range examined

Performance modelling and analysis of olympic class sailing boats

PhD ThesisThe work in this thesis is preceded by a Master of Research in Marine Technology project between September 2004 and October 2005. The project was supervised by Professor Martin Downie and was carried out with significant time present in the field, working closely with Olympic sailors from multiple different classes. This project was funded by UK Sport and considered a pilot project to investigate the feasibility of using data logging equipment with GPS in the marine Olympic environment. A series of prototype systems were engineered to meet the requirements specified by the Royal Yachting Association. The engineering and validation of the software and hardware formed a key part of the project to ensure that the results obtained were accurate and repeatable. This included software design within two different software platforms as well as embedded hardware developments. Significant testing and development were implemented in the laboratory as well as on the water during the beginning of the project and as a continuous background task throughout the project. Over eighty days were spent in the field developing and testing hardware and software as well as determining the optimum performance analysis methods. Data loggers were fitted to several Olympic class boats during the evaluation process to ascertain the performance of the data logging system as well as the performance of the boat and crew. Data was logged from the onboard GPS and accelerometers and analysed post training. Later in the project, wind information was also collected and fused together with the onboard data post training. The hypothesis was to demonstrate performance gains in the participating classes through the means of quantitative analysis. Prior to the project the performance analysis had been almost entirely qualitative. Through the course of the project various techniques were developed allowing quantitative performance analysis to supplement the efforts of the training group and coach. Key performance factors were determined by data analysis techniques developed during the project. One of the significant tools developed was a tacking performance analysis routine which analysed multiple different styles of tacks, calculating the distance lost with respect to wind strength and course length resulting in an important strategic tool. Other tools relating to starting performance and straight line speed were also developed in custom software allowing rapid analysis of the data to feed back to the teams in the debrief

Advanced Techniques for Design and Manufacturing in Marine Engineering

Modern engineering design processes are driven by the extensive use of numerical simulations; naval architecture and ocean engineering are no exception. Computational power has been improved over the last few decades; therefore, the integration of different tools such as CAD, FEM, CFD, and CAM has enabled complex modeling and manufacturing problems to be solved in a more feasible way. Classical naval design methodology can take advantage of this integration, giving rise to more robust designs in terms of shape, structural and hydrodynamic performances, and the manufacturing process.This Special Issue invites researchers and engineers from both academia and the industry to publish the latest progress in design and manufacturing techniques in marine engineering and to debate the current issues and future perspectives in this research area. Suitable topics for this issue include, but are not limited to, the following:CAD-based approaches for designing the hull and appendages of sailing and engine-powered boats and comparisons with traditional techniques;Finite element method applications to predict the structural performance of the whole boat or of a portion of it, with particular attention to the modeling of the material used;Embedded measurement systems for structural health monitoring;Determination of hydrodynamic efficiency using experimental, numerical, or semi-empiric methods for displacement and planning hulls;Topology optimization techniques to overcome traditional scantling criteria based on international standards;Applications of additive manufacturing to derive innovative shapes for internal reinforcements or sandwich hull structures

Three-dimensional single-sail static aeroelastic analysis & design method to determine sailing loads, shapes & conditions with applications for a FINN Class sail

The development of modern sailing boats has been based almost entirely on the cooperative efforts of enthusiastic skippers, designers and sail-makers, with very little contribution from scientists and technologists and using just basic scientific principles. In recent times, urgent and strong requests for improved performance, mostly for racing yachts, have guided the interest and the attention of the scientific community in the optimisation of sail performance and design approach. Sailing performance depends on the sailboat velocity, aerodynamic and hydrodynamic characteristics. This thesis focuses on the importance of the quantitative evaluation of the sail loads and how this contributes to the improvement of the performance of a sailboat through the development of a system for aiding sail design and assisting mast design. The objective of this study is to provide an integrated design system, which supplies analysis method and design features via a user-friendly graphical interface of a single-sail configuration. The major achievement is the development of an integrating numerical method, which evaluates loads and their distribution and the consequent deformed sail-shape. It improves sail performance analyses and design of new sails. Summarising, the major achievements are: • efficacy of accurate performance analysis for each sail, for any given shape over all the possible sailing courses; • critical investigation of the sail behaviour in the above-mentioned cases; improved approach to an integrated sail design; improvements in mast design from the structural and aerodynamic point of view; limited design costs, in terms of time consumed and computational power employed; efficacy of the visualisation of novel designed sail and predicted performance, which reduces the number of possible design flaws. hi conclusion, the integrated sail analysis and design system presented has important margins of improvements and diversification: extensions to non-homogeneous and anisotropic sailcloth, to two-sail configuration, windsurfs and integration of the mast

CFD prediction of the effect of appendages and leeway on the force trend of an Olympic class Laser dinghy hull

The purpose of this paper is to investigate whether the minima in hydrodynamic resistance can be predicted to occur at the same angles of heel and trim in the case of bare hull towing tank tests, bare hull simulations and appendage and leeway simulations. If so, the appendages and the leeway can be rejected from future investigations, which would prove a beneficial advancement, as they impose further complexity to simulations. The results of verification and validation (V&V) included in this paper demonstrate that the numerical method predicted too low resistance. Though the study identifies and systematically investigates possible sources of error, the major source of error was not found. These various possible sources of errors were identified for further research, and as future references for similar cases. Moreover, the simulation results for the variations of heel and trim also require further study. Before a full set of results is available, one cannot make conclusions regarding the angles of heel and trim that lead to minimal resistance. This paper discusses the results and potential avenues of future research, and is a result of an initiative at Chalmers University of Technology focusing on sports and technology

CFD prediction of the effect of appendages and leeway on the force trend of an Olympic class Laser dinghy hull

The purpose of this paper is to investigate whether the minima in hydrodynamic resistance can be predicted to occur at the same angles of heel and trim in the case of bare hull towing tank tests, bare hull simulations and appendage and leeway simulations. If so, the appendages and the leeway can be rejected from future investigations, which would prove a beneficial advancement, as they impose further complexity to simulations. The results of verification and validation (V&V) included in this paper demonstrate that the numerical method predicted too low resistance. Though the study identifies and systematically investigates possible sources of error, the major source of error was not found. These various possible sources of errors were identified for further research, and as future references for similar cases. Moreover, the simulation results for the variations of heel and trim also require further study. Before a full set of results is available, one cannot make conclusions regarding the angles of heel and trim that lead to minimal resistance. This paper discusses the results and potential avenues of future research, and is a result of an initiative at Chalmers University of Technology focusing on sports and technology