You dreamed of it since Weather4D Pro has featured its powerful routing module. He did it !
Our Toulousian crazy developer, Olivier Bouyssou, just sent Apple a new app : iPolar.
Developed in collaboration with — and on behalf of — KND SailingPerformance, iPolar calculates the performance polars of a sailboat based on specific parameters, Easy to identify :
- Overall Length (Length Over All)
- Waterline length (if unknown, iPolar will use a default value of 95% of LHT)
- Displacement
- Mainsail Surface
- Jib surface
- Spinnaker surface (optional)
- Asymmetrical spinnaker surface (optional)
Polars are calculated automatically as soon as the input is made. They can then be displayed in iPolar graph and table format :
The polars can then be exported directly to Weather4D PRO to feed the routing module (¹).
Explanations :
iPolar is a VPP (²) that predicts speed polars from a small number of parameters : length, Displacement and surface area of sails. This simplicity creates a number of restrictions : iPolar is designed only to correctly predict cruising and racing monohull polars. At time, only monohulls with a LOA between 8 meters. and 20 meters. are processed.
For sailboats whose parameters are outside the range provided for iPolar, the use of more advanced VPPs is required. KND-SailingPerformance uses NorthSails VPP, developed through several America's Cup cycles. Dans ce cas le VPP calcule les polaires à partir de matrices complètes de coefficients hydrodynamiques (issus de calculs de CFD) et de coefficients aérodynamiques. Au cas ou un tel VPP vous intéresse, contactez directement SailingPerformance.
KND SailingPerformance :
Cette petite société située à Valencia en Espagne a été fondée par trois ingénieurs de haut niveau dans les domaines de la modélisation mathématique, de l’architecture navale et de l’analyse des performances. Ils se sont fait une réputation grâce à leur expertise appliquée à la course au large depuis plus de dix ans, actively assisting famous boats in America's Cup, la Volvo Ocean Race, Vendée Globe, and many others.
Pour obtenir les données des bateaux, vous pourrez vous référer aux sites web spécialisés, comme en France l’excellent Select A boat de François Kammerer, a compatriot from Loire-Atlantique.
iPolar should be available in a few days on the Apple AppStore at the price of 9,99 €. We will be sure to talk about it again during the Nautic, at the iTabNav.fr booth (Hall 2.1 – Booth D41).
—
(¹) See my post Routing comes up in Weather4D PRO 1.3
(²) Velocity Predicting Program
—
I have just made a comparison of the calculation of the polars of my boat by Ipoar with what I had already noted in estimation on the 3 Later years of sailing.
The calculation seems very close to me. So I would rather have a favorable opinion on this application. Anyway for people like me who use routing safely and not for racing it's more than enough.
Congratulations to Francis and Olivier who continue to concoct high-performance tools at a reduced cost.
Their work is greatly appreciated.
BQ
Bonjour,
I'm interested in knowing the polars on my boat. They will allow me to use W4D pro routing.
I have a special boat. It is rigged in houari cutter. I have a large houari sail, at the bow a staysail and a jib. I also have a genaker.
Can this rig be suitable for ipolar.
Thank you.
Fufu.
The best thing to do is to ask the publisher of the application directly, SailingPerformance, which you have the link in a comment above.
Bonjour,
Thank you for this information.
Aren't there plans for an app that builds speed polars in real time ? It would then boat specific data, sails state, au talent du barreur ! 🙂
To build a polar, si je ne m’abuse, must : boat speed, wind speed and direction. All these information can be available as NMEA data, isn't it ?
Remarque complémentaire : often standard boats polars are given by the builder or architect.
Bonjour,
Bonne remarque. Les polaires idéales existent pour un certain nombre de bateaux. However for each value they take into account configuration of the sails and a more efficient displacement configuration… (laquelle d’ailleurs ? souvent de course en pratique).
iPolar allows to vary these parameters as well as the user wishes and answer questions such: How can I lose to such a leg not using my spinnaker ?
La deuxieme question est tout a fait pertinente. Performance analysis from data at sea to improve polars and various targets (heel, rudder, etc,…) est une de nos activités principales. Dans ce domaine nous avons travaillé cette année avec des équipes qui incluent Groupama, Camper, Macif, Poujoulat, Quantum Racing, WildOats… Une fois la connection établie (nous sommes bien d’accord que ca n’est pas le plus difficile) two obstacles to overcome :
1) Calibration of electronic devices. Si il est relativement facile de calibrer la vitesse, le vent réel est un sujet nettement plus complexe. It also faces a coupling phenomena such as heel and speed (cette année 5% speed difference observed between 0 ° and 25 ° heel on a mini maxi…)
2) Errors induced by the processing of instantaneous data : actually your boat will artificially excellent performance every time you leave a gust to enter into a calm. To handle this problem our professional tools for advanced data filtering to eliminate transitions.
Nous refléchissons à développer et proposer des versions iOS grand public de ces outils… work in progress as said !
Un grand merci à SailingPerformance pour ces intéressantes précisions 🙂