scholarly journals VPP-Driven Sail and Foil Trim Optimization for the Olympic NACRA 17 Foiling Catamaran

2021 ◽  
Vol 5 (01) ◽  
pp. 61-81
Author(s):  
Kai Graf ◽  
Oliver Freiheit ◽  
Paul Schlockermann ◽  
Jan C. Mense
Keyword(s):  
Olympic Games ◽  
Strong Impact ◽  
Large Set ◽  
Prediction Program ◽  
Velocity Prediction ◽  
Rudder Angle ◽  
Boat Speed ◽  
The Olympic Games

Abstract. The Nacra-17 catamaran is currently the only type of multihull that participates in the Olympic Games. It features semi-L-shaped daggerboards, allowing the boat to foil. For maximizing boat speed, the sailors have to cope with a large set of trimming parameters. Boat speed depends on sail trim, but additional trim parameters also have a strong impact on boat speed: the rake of the daggerboard and the rudder, the platform trim and heel angle and the rudder angle. The project described here tries to assist the sailors in finding an optimized set of trim parameters. This is done with the help of a proprietary velocity prediction program, which - besides solving for equilibrium of all forces acting on the boat - searches for the set of daggerboard and rudder rake, rudder angle, heel angle and platform trim, for which performance yields a maximum. The paper describes the method as well as some of the results.

Added Resistance in Seaways and its Impact on Yacht Performance

2007 ◽  
Author(s):  
Kai Graf ◽  
Marcus Pelz ◽  
Volker Bertram ◽  
H. Söding
Keyword(s):  
Strong Impact ◽  
Wave Spectra ◽  
Linear Extensions ◽  
Added Resistance ◽  
Optimum Length ◽  
Prediction Program ◽  
Strip Theory ◽  
Velocity Prediction ◽  
Added Resistance In Waves ◽  
Response Amplitude Operators

A method for the prediction of seakeeping behaviour of sailing yachts has been developed. It is based on linear strip theory with some non-linear extensions. The method is capable to take into account heeling and yawing yacht hulls, yacht appendages and sails. The yacht's response amplitude operators (RAO) and added resistance in waves can be predicted for harmonic waves as well as for natural wave spectra. The method is used to study added resistance in seaways for ACC-V5 yachts of varying beam. Results are used for further VPP investigations. The AVPP velocity prediction program is used to study optimum length to beam ratio of the yachts depending on wind velocity and upwind to downwind weighting. This investigation is carried out for flat water conditions as well as for two typical wave spectra. The results show that taking into account added resistance in seaways has a strong impact on predicted performance of the yacht.

Prediction and Optimization of Aerodynamic Forces and Boat Speed of Foiling Catamaran with a Rig of a Rigid Wing and a Jib

2016 ◽  
Author(s):  
Kai Graf ◽  
Hannes Renzsch ◽  
Janek Meyer
Keyword(s):  
Optimization Method ◽  
Hydrodynamic Flow ◽  
Design Parameters ◽  
Constraint Optimization ◽  
Aerodynamic Forces ◽  
Force Prediction ◽  
Prediction Program ◽  
Velocity Prediction ◽  
Rigid Wing ◽  
Boat Speed

This paper describes a method to calculate the aerodynamic forces generated by a rigid two-element wing together with a jib. Additionally, investigations of hydrodynamic flow forces generated by water-piercing L-shaped foils are introduced. The aerodynamic and hydrodynamic flow force prediction methods are combined in a velocity prediction program featuring a constraint optimization method in order to predict boat speed and wing and foil trimming parameters for its maximization. A velocity polar calculated by applying this method to a 50-foot catamaran is shown and the result of some studies are presented, varying design parameters of the catamaran.

PCSAIL, A Velocity Prediction Program for a Home Computer

2001 ◽  
Author(s):  
David E. Martin ◽  
Robert F. Beck
Keyword(s):  
Design Stage ◽  
Rapid Evaluation ◽  
University Of Michigan ◽  
Prediction Program ◽  
Other Information ◽  
Velocity Prediction ◽  
Turn Around Time ◽  
Excel Solver ◽  
The University ◽  
Boat Speed

An Excel Velocity Prediction Program has been developed to allow for rapid evaluation of yacht performance at the initial design stage. The required input consists of only the basic hull and sail dimensions. Empirical equations, based on these basic dimensions, are used for initial estimates of required hull parameters. As the design progresses the user can easily replace these default values with refined estimates or actual values. Because of its simplicity, and short turn around time, the program has been used as a teaching aid at the University of Michigan. Reconstruction of the program, PCSAIL, may be made with equations and other information provided in the Appendix. The Excel "Solver" has been found to be a reliable means of finding the equilibrium boat speed and heel angle. It seeks the maximum boat speed by adjusting the sail flattening factor, F, and reef, R, and the lateral location of the "movable crew." In the case of a hinged centerboard, or dagger- board, it will also adjust the draft for maximum boat speed. For sloop rigs the program will also take in the jib and set the spinnaker, at the appropriate wind angle, in order to gain maximum boat speed. The program plots the speed "polar," and velocity made-good, and determines the tacking angles.

Improvement of Sailing Yacht Performance Prediction by Including Force-Moment Equilibrium for the Calculation of Helm Angle in a Velocity Prediction Program

1995 ◽  
Author(s):  
Peter van Oossanen
Keyword(s):  
Mathematical Model ◽  
Performance Prediction ◽  
Model Tests ◽  
Side Force ◽  
Prediction Program ◽  
Moment Equilibrium ◽  
Force Moment ◽  
Velocity Prediction ◽  
Sailing Yacht ◽  
Rudder Angle

Contemporary Velocity Prediction Programs (VPP's) consider the equilibrium of forces acting on a sailing yacht in the thrust direction and in the direction of the developed side force on canoe body and appendages. In addition, force-moment equilibrium is considered in the transverse plane of the yacht. In this way a solution is found for the three main unknowns in performance prediction, viz: boat speed, leeway angle and heel angle. The impact of helm angle on performance is herein ignored. In the velocity prediction program developed by Van Oossanen & Associates, a fourth equilibrium condition is included, viz: force-moment equilibrium in the horizontal plane for the calculation of the helm angle required for the equilibrium sailing condition. In this paper a description is given of some of the main problems that need to be solved when introducing this fourth equilibrium requirement. One of these is associated with the development of accurate mathematical expressions for the calculation of rudder side force and resistance, as influenced by heel angle and the proximity of the free surface. Model tests can be utilized for obtaining insight into the physical phenomena involved in such cases. Model tests were carried out in the context of an optimization study for the design of a yacht according to the International Level Class 40 (ILC40) Rule, under the International Measurement System (IMS). The analysis of some of the results of these tests with respect to improving the mathematical model for rudder side force and resistance, is described in the paper. The effect of including this mathematical model in a VPP is demonstrated in the paper by providing the results of calculations which reveal that a variation in rudder angle causes significant speed differences. It is shown that the IMS VPP that is used to calculate the rating and speed potential of ILC40 and other IMS Class yachts, in not taking into account the significant variations in performance associated with different values of the equilibrium rudder angle (and the associated rudder side force and resistance), is not sufficiently accurate.

The Effects of Significant International Sports Events on Hungarian Suicide Rates

Crisis ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Karoly Bozsonyi ◽  
Peter Osvath ◽  
Sandor Fekete ◽  
Lajos Bálint
Keyword(s):  
Significant Relationship ◽  
Olympic Games ◽  
Arima Model ◽  
Age Groups ◽  
The Elderly ◽  
Intervention Analysis ◽  
Middle Aged ◽  
Sports Events ◽  
Sport Events ◽  
The Olympic Games

Abstract. Background: Several studies found a significant relationship between important sport events and suicidal behavior. Aims: We set out to investigate whether there is a significant relationship between the raw suicide rate and the most important international sports events (Olympic Games, FIFA World Cup, UEFA European Championship) in such an achievement-oriented society as the Hungarian one, where these sport events receive great attention. Method: We examined suicide cases occurring over 15,706 days between January 1, 1970, and December 31, 2012 (43 years), separately for each gender. Because of the age-specific characteristics of suicide, the effects of these sport events were analyzed for the middle-aged (30–59 years old) and the elderly (over 60 years old) generations as well as for gender-specific population groups. The role of international sport events was examined with the help of time-series intervention analysis after cyclical and seasonal components were removed. Intervention analysis was based on the ARIMA model. Results: Our results showed that only the Olympic Games had a significant effect in the middle-aged population. Neither in the older male nor in any of the female age groups was a relationship between suicide and Olympic Games detected. Conclusion: The Olympic Games seem to decrease the rate of suicide among middle-aged men, slightly but significantly.

Book Review

2016 ◽  
Vol 6 (2) ◽  
pp. 386-389
Author(s):  
Eduardo Oliveira
Keyword(s):  
Urban Planning ◽  
Urban Design ◽  
Olympic Games ◽  
City Image ◽  
European Capital Of Culture ◽  
The Arts ◽  
The World ◽  
The City ◽  
The Olympic Games

Evinç Doğan (2016). Image of Istanbul, Impact of ECoC 2010 on The City Image. London: Transnational Press London. [222 pp, RRP: £18.75, ISBN: 978-1-910781-22-7]The idea of discovering or creating a form of uniqueness to differentiate a place from others is clearly attractive. In this regard, and in line with Ashworth (2009), three urban planning instruments are widely used throughout the world as a means of boosting a city’s image: (i) personality association - where places associate themselves with a named individual from history, literature, the arts, politics, entertainment, sport or even mythology; (ii) the visual qualities of buildings and urban design, which include flagship building, signature urban design and even signature districts and (iii) event hallmarking - where places organize events, usually cultural (e.g., European Capital of Culture, henceforth referred to as ECoC) or sporting (e.g., the Olympic Games), in order to obtain worldwide recognition. 

Metaphorik im Kommunikationsbereich der Sportfachsprachlichkeit

Fachsprache ◽  
2019 ◽  
Vol 41 (S1) ◽  
pp. 87-100
Author(s):  
Wenke Mückel
Keyword(s):  
Olympic Games ◽  
Special Kind ◽  
European Football ◽  
Sport Events ◽  
The Olympic Games

Metaphorical elements are a highly productive language means in live reports about sport events on TV. They occur in different relations to what is simultaneously seen on screen and depend on the reporter as well as on the special kind of sport. But nevertheless, general structures and functions of metaphors in those medium-bound oral texts can be indicated; as one of the markers they contribute to what is often called language of sport or maybe rather communicative template of sport. Examples taken from TV reports of the European Football Championship and the Olympic Games (both took place in 2016) are used to illustrate this character of metaphorical expressions in sport reports on TV.

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