Analysis of the Performance and Sailing Variables of the Optimist Class in a Variety of Wind Conditions (original) (raw)

Visual search, movement behaviour and boat control during the windward mark rounding in sailing

Journal of sports sciences, 2015

In search of key-performance predictors in sailing, we examined to what degree visual search, movement behaviour and boat control contribute to skilled performance while rounding the windward mark. To this end, we analysed 62 windward mark roundings sailed without opponents and 40 windward mark roundings sailed with opponents while competing in small regattas. Across conditions, results revealed that better performances were related to gazing more to the tangent point during the actual rounding. More specifically, in the condition without opponents, skilled performance was associated with gazing more outside the dinghy during the actual rounding, while in the condition with opponents, superior performance was related to gazing less outside the dinghy. With respect to movement behaviour, superior performance was associated with the release of the trimming lines close to rounding the mark. In addition, better performances were related to approaching the mark with little heel, yet heel...

Sail optimization for upwind sailing: application in a Tornado, the Olympic class catamaran

Journal of Marine Science and Technology, 2008

A study of a boat's motion is carried out in order to analyze the aerodynamic properties of the optimal sail for obtaining the maximum velocity when sailing to windward. The mechanics study shows the optimal CL and CQ for a given sail and how the shape of the aerodynamic polar of the sail should be. A parametrical analysis of the aerodynamics of a sail is then carried out varying the maximum camber, position of the maximum camber in the chord direction and position of the maximum camber in the mast direction. The parametric analysis is done numerically with a vortex lattice method (VLM) and experimentally in a wind tunnel. The results show that the influence of the relevant parameters studied can be reduced to the variation of two parameters, A and B, defining the polar of the sail, Co = B + A 2 C^; and the influence of parameters A and B on the maximum VMG obtainable are calculated.

Climatic Analysis of Wind Patterns to Enhance Sailors’ Performance during Races

Climate, 2021

The impact of environmental and meteorological conditions when dealing with sport performance has been demonstrated by several studies carried out in recent years. Among the meteorological variables with the greatest effect are temperature, humidity, precipitation, and wind direction and speed. This research focused on analyzing and forecasting the wind patterns occurring in Enoshima Bay (Japan). In particular, the objective of this study was to provide support and guidance to sailors in the preparation of the race strategy, thanks to an in-depth knowledge of these meteorological variables. To do this, an innovative method was used. First, through the combined use of Weather Research and Forecasting (WRF) and CALMET models, a simulation was performed, in order to reconstruct an offshore database of a recent 10-year period (2009–2018) over the race area, inside the bay. Subsequently, the verification of hind-cast was performed: the wind data measured at sea were compared with the dat...

Optimization of upwind sailing applying a canting rudder device

Ocean Engineering

The research explained in this paper was carried out to investigate the efficiency of different steering systems on sailing yachts. The steering system of a sailing yacht mostly includes a simple steering system and a hydrodynamic shaped single rudder, or multiple rudders, depending on boat characteristics. One of the basic design guidelines for fast sailing yachts involves reducing the wetted surface to the minimum allowed by the dynamic stability while maintaining the optimal sailing performances. Deficiencies of different steering systems are discussed and their influences on total lift and yaw moments; yacht manoeuvrability in different sailing directions is also analysed. The discussion is focused on steering systems applicable in practice and accepted by the yacht-building industry, although several innovations may be found that remained in their development stage because of their complexity in construction, maintenance, use itself and reliability. The canting rudder is analys...

Mathematical Theory of Sailing

2009

We show by computational solution of the incompressible Navier-Stokes equations with friction force boundary conditions, that the classical inviscid circulation theory by Kutta-Zhukovsky for lift and laminar viscous boundary layer theory by Prandtl for drag, which have dominated 20th century fluid dynamics, do not correctly describe the real turbulent airflow around a sail under tacking. We show that lift and drag essentially originate from a turbulent wake of counter-rotating rolls of low-pressure streamwise vorticity generated by a certain instability mechanism of potential flow at rear separation. The new theory opens the possibility of ab initio computational prediction of characteristics of a sailing boat using les than a million meshpoints without resolving thin boundary layers, instead of the imposssible quadrillions required according to state-of-the-art for boundary layer resolution.

Assessment of upwind dinghy sailing performance using a virtual reality dinghy sailing simulator

Journal of Science and Medicine in Sport, 1998

The ability of fourteen competitive helmsmen of different skill levels to sail a standard course towards the wind (upwind) was assessed using a virtual reality sailing simulator. The simulator consisted of a Laser dinghy deck which pivoted between two supports and was dynamically controlled by a computer driven pneumatic ram. Computer generated graphics realistically reproduced helming, sheeting, tacking and boat trim. After familiarisation with the simulator, subjects performed a standard lkm upwind test and were ranked according to their completion time. The subjects were then asked to fill out a questiolmaire to obtain an estimate of how effectively the simulator reproduced the conditions of actual sailing. Mean scores showed the sailors considered overall feel and simulation of physical movement as "good" (5 on a scale of 1 to 6). Ranldngs for the upwind test were compared with independent competition rankings for each subject. Overall time to complete the upwind test correlated well with a subject's external ranking (Spearlnan's rank order r=0.99). The results indicate that the test used can differentiate between variations in upwind sailing performance over a wide range of ability. The simulator thus provides for the first time a method of measuring and analysing a sailor's performance in a controlled laboratory setting.

Assessing the wind-heel angle relationship of traditionally-rigged sailing vessels

2009

A program to assess the wind-heel relationship of traditionally-rigged sailing vessels has been undertaken with the eventual goal of being able to provide sailing guidance to the masters and crews. This program uses Computational Fluid Dynamics (CFD) with full-scale experimental measurement to develop and validate a windheel model, as well as understand the nature of how these vessels respond to different wind situations. The CFD simulations are used to assess errors in measured wind angle and direction, and the experimental data are used to establish the CFD model uncertainty. The model has been validated against a limited set of data from Pride of Baltimore II. In some cases the agreement between the model and experimental values is excellent; in other cases there is significant error. The CFD-based model is computationally expensive, so a different approach for determining the sail forces is proposed. The experimental measurements indicate that the ship is almost never in static ...