Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Design > Stability
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 01-28-2010, 09:42 AM
burley1 burley1 is offline
Junior Member
 
Join Date: Jan 2010
Rep: 10 Posts: 12
Location: UK
calculating heal

can any one help. I'm trying to calculate what wait is needed for a 14 ft sailing dingy, and weather I need a trapeze. the formula that I'm using is, the force in the sails x the hight of the CE x the depth of the CLR x the force against the dagerboard. but is there any set wind force used in this equation. and is the force on the dagerboard = the force of the wind?
thanks for any help you can give me.
cheers
Reply With Quote
  #2  
Old 01-29-2010, 09:30 AM
gonzo's Avatar
gonzo gonzo is offline
Senior Member
 
Join Date: Aug 2002
Rep: 1493 Posts: 7,447
Location: Milwaukee, WI
You need to substact the force created by the stability of the hull
__________________
Gonzo
Reply With Quote
  #3  
Old 01-29-2010, 05:40 PM
burley1 burley1 is offline
Junior Member
 
Join Date: Jan 2010
Rep: 10 Posts: 12
Location: UK
thanks for the reply gonzo
I am currently working to get a place at a university to study marine architecture, and this is sort of a project to show them.
as I have no training in this field I am very sketchy on the theory behind all of the analysis work.
one problem that I'm having is that this is a sailing dingy and will no doubt be top heavy, relying on the crews wait to keep her upright. does the stability of the hull + rig still play a roll in the equation when there is no self righting factor ( waited keel or ballast).
this design is very similar in shape to the Merlin rocket. if that helps at all.
thanks for all your help
cheers
Reply With Quote
  #4  
Old 01-29-2010, 06:10 PM
gonzo's Avatar
gonzo gonzo is offline
Senior Member
 
Join Date: Aug 2002
Rep: 1493 Posts: 7,447
Location: Milwaukee, WI
There will be some initial stability. That is why the boat can float upright without a crew. It isn't much though. The easiest way to know if you are on the right track, is to look at dinghies that have or not trapeze. See what your calculations show for each.
__________________
Gonzo
Reply With Quote
  #5  
Old 01-30-2010, 10:50 AM
burley1 burley1 is offline
Junior Member
 
Join Date: Jan 2010
Rep: 10 Posts: 12
Location: UK
is this something that is used allot in dingy design? or is it more common to guesstimate for smaller boat such as this. as there as lots of variables that can play a part on a boat this size.
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Calculating risk watchkeeper Boat Design 15 11-01-2009 12:15 PM
Calculating Bevels ajmoir Boat Design 28 12-05-2005 04:49 PM
Calculating the speed huntermike32 Propulsion 27 11-14-2005 02:39 PM
calculating GZ UNOSNAME Boat Design 6 11-04-2004 05:06 AM
calculating displacement 8knots Boat Design 2 03-21-2002 01:57 AM


All times are GMT -5. The time now is 06:10 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net