Performance Prediction without Empiricism: A RANS-Based VPP and Design Optimization Capability

2007 ◽  
Author(s):  
Richard Korpus
Keyword(s):  
Design Optimization ◽  
Performance Prediction ◽  
Real World ◽  
Development Effort ◽  
New Approach ◽  
Flow Features ◽  
Velocity Prediction ◽  
Sailing Yacht ◽  
America’S Cup ◽  
Force Data

The use of Velocity Prediction Programs (VPP’s) in sailing yacht design has been standard practice for years. VPP fidelity, however, continues to be limited by the accuracy of aero and hydro force data used to represent a particular yacht. Even the most advanced America’s Cup VPP’s usually derive sail forces from panel or vortexlattice models, and hull forces from potential flow codes or experiment. Real world effects attributed to viscosity are added using simplified theoretical or empirical models that cannot resolve all the complexity of sailboat physics. This paper describes a new approach for performance prediction and design optimization that relies solely on high-resolution Reynolds-Averaged NavierStokes (RANS) computational fluid dynamics. All aero and hydro forces and moments are generated by RANS, and therefore include the real-world flow features of boundary layers, separation, shed vorticity, and turbulence. RANS software and grid model requirements suitable for VPP applications are discussed, and sample aero and hydro solutions included. Examples from America’s Cup design are used to demonstrate the technique’s practicality and accuracy. Finally, since VPP’s require forces from a large number of sailing conditions, the extensive development effort (undertaken through three America’s Cup cycles) to transition state-of-the-art RANS into the practical realm is summarized.

Performance Prediction Hoftware for IACC Yachts

1993 ◽  
Author(s):  
Eric C. Schlageter ◽  
James R. Teeters
Keyword(s):  
Performance Prediction ◽  
Linear Optimization ◽  
Viscous Drag ◽  
Development Effort ◽  
Added Resistance ◽  
Induced Drag ◽  
Software Development Effort ◽  
Tank Test ◽  
America’S Cup ◽  
Wetted Area

The performance prediction software development effort undertaken by the Partnership for America's Cup Technology (PACT) is reviewed. First, PACT's origin, members, and mandate is covered, interspersed with a historical perspective of prediction software. Next, the new IACC rule with constraints is given. The hydrodynamic model format used in the software is described. Based on PACT tank test data, improved formulations for viscous drag, utilizing dynamic wetted area and length for canoe body drag and a 'stripping' method for appendage drag are presented. Corrections for Froude number and heel effects on induced drag are summarized. A new upwind sail model and added resistance model are discussed. The use of a race modeling program is illustrated with results from three separate design studies: a geosim family, a length scaling family, and an appendage study. Typical upright resistance, drag polar plots, lift plots, sea spectra, and added resistance data are presented. The final section describes current developments including speed enhancements, improved portability, and use of a multi-variable, non-linear optimization scheme to search the design space.

Performance Prediction Method for Multihull Yachts

1989 ◽  
Author(s):  
Clay Oliver
Keyword(s):  
Performance Prediction ◽  
State Of The Art ◽  
Prediction Method ◽  
Aerodynamic Forces ◽  
Design Studies ◽  
Performance Predictions ◽  
Velocity Prediction ◽  
America’S Cup ◽  
And Performance ◽  
Scale Data

A new performance prediction method for multihull yachts is described. The methods described here, and performance predictions based on these methods were used in the design and modifications of the 1988 America's Cup Defender Stars & Stripes. The method incorporates the type of solution procedures used in state-of-the-art monohull velocity prediction programs. The various models used for hydrodynamic and aerodynamic forces are briefly discussed. The predictive method is validated using full-scale data from C-Class catamarans, a Formula 40 catamaran, a 75-foot “maxicat”, and Stars & Stripes with a soft-sail rig. Several examples of design studies are presented.

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.

scholarly journals Science of the 470 Sailing Performance

2020 ◽  
Vol 5 (01) ◽  
pp. 20-46
Author(s):  
Yutaka Masuyama ◽  
Munehiko Ogihara
Keyword(s):  
High Performance ◽  
World Wide ◽  
Academic Research ◽  
Research Community ◽  
Research Association ◽  
Velocity Prediction ◽  
Sailing Yacht ◽  
America’S Cup

This paper holds a significant place in the Journal of Sailing Technology, as the very last publication of Prof. Masuyama, published posthumously, and co-authors by Dr. Ogihara. For many decades, Prof. Masuyama has been a very influential and respected member of the sailing yacht research community world-wide, holding the chairmanship of the Sailing Yacht Research Association of Japan for close to 20 years, and being involved with the Japanese America’s Cup Challenge. His expertise and academic research have impacted generations of researchers, and his work on high performance sails, sailing yachts and velocity prediction remains at the forefront of sailing technology. It is therefore with great honour that the Journal of Sailing Technology presents the very last insights of Prof. Masuyama into the sailing performance of the 470 Olympic class dinghy.

scholarly journals Simplification and Detection of Outlying Trajectories from Batch and Streaming Data Recorded in Harsh Environments

2019 ◽  
Vol 8 (6) ◽  
pp. 272 ◽  
Author(s):  
Iq Reviessay Pulshashi ◽  
Hyerim Bae ◽  
Hyunsuk Choi ◽  
Seunghwan Mun ◽  
Riska Asriana Sutrisnowati
Keyword(s):  
South Korea ◽  
Real World ◽  
Experimental Evaluation ◽  
Streaming Data ◽  
Harsh Environments ◽  
Noise Filtering ◽  
New Approach ◽  
Detection Algorithms ◽  
Outlying Point

Analysis of trajectory such as detection of an outlying trajectory can produce inaccurate results due to the existence of noise, an outlying point-locations that can change statistical properties of the trajectory. Some trajectories with noise are repairable by noise filtering or by trajectory-simplification. We herein propose the application of a trajectory-simplification approach in both batch and streaming environments, followed by benchmarking of various outlier-detection algorithms for detection of outlying trajectories from among simplified trajectories. Experimental evaluation in a case study using real-world trajectories from a shipyard in South Korea shows the benefit of the new approach.

Between Real and Ideal: Documenting Media Art

Leonardo ◽  
2008 ◽  
Vol 41 (4) ◽  
pp. 418-419 ◽  
Author(s):  
Caitlin Jones ◽  
Lizzie Muller
Keyword(s):  
Data Structure ◽  
Real World ◽  
Media Art ◽  
New Approach ◽  
The Real ◽  
Key Features ◽  
The Ideal

This paper describes a new approach to documenting media art which seeks to place in dialogue the artist's intentions and the audience's experience. It explicitly highlights the productive tension between the ideal, conceptual existence of the work, and its actual manifestation through different iterations and exhibitions in the real world. The paper describes how the approach was developed collaboratively during the production of a documentary collection for the artwork Giver of Names, by David Rokeby. It outlines the key features of the approach including artist's interview, audience interviews and data structure.

scholarly journals Stadium Norm and Douglas-Rachford Splitting: A New Approach to Road Design Optimization

2016 ◽  
Vol 64 (1) ◽  
pp. 201-218 ◽  
Author(s):  
Heinz H. Bauschke ◽  
Valentin R. Koch ◽  
Hung M. Phan
Keyword(s):  
Design Optimization ◽  
New Approach ◽  
Road Design

Investigation of Scale Effects in Sailing Yacht Performance Prediction by Experimental Methods

2013 ◽  
Author(s):  
Mustafa Insel ◽  
Ziya Saydam
Keyword(s):  
Performance Prediction ◽  
Research Study ◽  
Scale Effects ◽  
Waiting Times ◽  
Wave Pattern ◽  
Experimental Investigations ◽  
The Past ◽  
Scale Models ◽  
Sailing Yacht ◽  
Testing Techniques

A substantial amount of research has been carried out in the past to enhance the testing techniques and to increase the accuracy associated with tank testing of sailing yachts. The majority of this work was associated with high budgeted campaigns; large models, long waiting times and high budgets became standard practice in the field. This led to lack of accessibility for low budgeted campaigns and for designers of ordinary sailing yachts to these tests. A research study has been initiated to investigate the scale effects associated with tank testing of sailing yachts. The intention has been to make best use of modern experimental and computational methods to understand the scale effects in conjunction with systematic tank tests. Both viscous and wave components were considered for investigation of scale effects in sailing yacht performance prediction. Four different scale models ranging from 1/4 to 1/10 of a TP52 yacht have been tested in the towing tank in upright and heeled condition while full, half and quarter scale computational analysis have been carried out with a RANS code. The wave pattern measurements were conducted for all upright and heeled cases with the use of three wave probes on each side. Variation of drag, side force, running attitude and wave pattern have been investigated. This paper focuses on the experimental investigations both in the upright and heeled conditions.

scholarly journals Μέθοδοι σχεδιασμού-βελτιστοποίησης στις στροβιλομηχανές βασισμένες στους εξελικτικούς αλγορίθμους

2013 ◽  
Author(s):  
Στυλιανός Κυριάκου
Keyword(s):  
Design Optimization ◽  
Real World ◽  
Large Scale ◽  
Optimization Methods ◽  
Industrial Applications ◽  
Turn Around Time ◽  
Phd Thesis

The scope of this PhD thesis is to pΙopose a set of improvements to existingshape design-optimization methods in fluid dynamiοs based on EvolutionaryΑlgorithms (EAs) and demonstrate their effiοienοy in real-world applications.Though the proposed method and the developed EA-based software are bothgeneriο, this thesis foοuses on applicatiοns in the fields of hydrau1ic andthermal turbomaοhines. With the proposed a1gorithmic variants, theoptimization turn-around time is notiοeably reduοed with respeοt to that ofοonventional (reference, background) methods. Though the latter areοomputationally expensive, with the proposed add-ons, they becomeaffordable even for large-scale industrial applications.

scholarly journals Putting resilient sustainability into strategy decisions – case studies

2018 ◽  
Vol 56 (7) ◽  
pp. 1598-1612 ◽  
Author(s):  
Julie Winnard ◽  
Jacquetta Lee ◽  
David Skipp
Keyword(s):  
Case Studies ◽  
Real World ◽  
Design Methodology ◽  
Strategic Decision ◽  
New Approach ◽  
Content Type ◽  
Industrial Companies ◽  
Different Types ◽  
Strategic Decision Support ◽  
Practical Implications

Purpose The purpose of this paper is to report the results of testing a new approach to strategic sustainability and resilience – Sustainable Resilient Strategic Decision-Support (SuReSDS™). Design/methodology/approach The approach was developed and tested using action-research case studies at industrial companies. It successfully allowed the participants to capture different types of value affected by their choices, optimise each strategy’s resilience against different future scenarios and compare the results to find a “best” option. Findings SuReSDS™ enabled a novel integration of environmental and social sustainability into strategy by considering significant risks or opportunities for an enhanced group of stakeholders. It assisted users to identify and manage risks from different kinds of sustainability-related uncertainty by applying resilience techniques. Users incorporated insights into real-world strategies. Research limitations/implications Since the case studies and test organisations are limited in number, generalisation from the results is difficult and requires further research. Practical implications The approach enables companies to utilise in-house and external experts more effectively to develop sustainable and resilient strategies. Originality/value The research described develops theories linking sustainability and resilience for organisations, particularly for strategy, to provide a new consistent, rigorous and flexible approach for applying these theories. The approach has been tested successfully and benefited real-world strategy decisions.

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