Ver mensaje
  #4510  
Antiguo 22-03-2011, 16:00
Avatar de Cedemont
Cedemont Cedemont esta desconectado
Hermano de la costa
 
Registrado: 09-06-2009
Localización: Atlantico y Mediterraneo
Edad: 60
Mensajes: 3,113
Agradecimientos que ha otorgado: 366
Recibió 1,312 Agradecimientos en 611 Mensajes
Sexo:
Predeterminado Re: Veleros que aguantan el mal tiempo y los que nunca lo haran

Para los neofitos del tema estabilidad:

"Sailing Vessel Stability Criteria

To judge adequacy of stability is a complex matter.
For sailing vessels, many have proposed a simple criteria based on a prescribed "range of positive stability." While relatively easy to assess and therefore tempting as a simple method, this is not a complete or necessarily adequate picture. Stability is a dynamic event and is affected by quite a number of different vessel parameters.
The most recent methods for assessing a sailing vessel's "dynamic" stability have been provided in two forms:
First, a proposed method is presented in Principles of Yacht Design, by Larsson & Eliasson. It is called simply the Dynamic Stability Factor (DSF). The DSF is the result of work done by Moon and Oossanen to propose a rational criteria based an a number of factors that contribute to a vessel's sea keeping ability. The factors are calculated which analyze Beam vs. Displacement; Sail Area along with Displacement, Beam and Length; Displacement to Length; Self Righting Energy; and finally the Relative Areas of the Positive vs. the Negative Stability Curves. A DSF "score" is accumulated and the vessel is rated for Ocean; Offshore; Inshore; or Sheltered waters.
Second, the DSF method was then expanded to include input from designers world wide and a refined method derived. The results of this research have been presented by Oossanen in a publication of the Chesapeake Sailing Yacht Symposium. This new method is provisionally being used as the standard within the European Union (Specifically, ISO-12217). It is referred to simply as the Stability Index (STIX). Although the STIX formulae differ completely from those used by the DSF method, the STIX method takes a similar approach. STIX analyses Righting Energy; Inversion Recovery; Knockdown Recovery; Displacement to Length; Beam to Displacement; Wind Moment; Downflooding Angle; and the vessel's Base Size. The resulting factors are accumulated into a "score" which again rates a vessel for Ocean; Offshore; Inshore; or Sheltered waters.
While many other criteria have been proposed, the DSF and STIX methods are by far the most comprehensive, and provide the greatest amount of information about a sailing vessel's survivability. "




Fuente:http://www.kastenmarine.com/design_calcs.htm


Esa es la razon por la que hay veleros que aguantan el mal tiempo y otros que aunque lo intenten...nunca lo haran. El STIX divide a los veleros segun categorias de navegacion y nunca debe intentarse meterse en condiciones para las que no esta preparado nuestro barco.

Hay modelos de 28 pies con un alto STIX y otros con muchos pies mas que acusan fallos de diseño por sobredimensionamiento del plano velico, por bajo AVS,por poca potencia del par adrizante,o por angulos de inundacion demasiado bajos. Atencion a futuros armadores.


__________________
Cedemont

El hilo del STIX,"Veleros que aguantan el mal tiempo y los que nunca lo harán"

Editado por Cedemont en 22-03-2011 a las 16:04.