slow slew

[convict]

Is it possible to find information about the dynamic forces when a boat slews towards a right angle and skids along the original path ? It seems that resistance force increases from the normal perpendicular at about .25 the resistance increase from forward line of around twice original drag. Is this the crude amount of change of motion? This is only for the rough estimate not the equations or details of waves , turbulence or hull shape .

 

[sarabande]

Amateur Yacht Research Society has a library on hydrodynamics.

http://www.dcss.org/ayrs/6.html

 

[lpdsn]

As I understand it there is standard data available for a whole range of foil shapes so it would depend a lot of the keel and rudder, even neglecting the effect of the hull. I have Fossati's book but it's two or three years since I last looked at it, so I'll see if I can find anything in there.

 

[lpdsn]

Had a quick skim read about the NACA series of foils but these don't seem to go up to the angles of attack you're considering.

 

[convict]

Thank you all. Amateur Y research says: This site can’t be reached
ourworld.compuserve.com’s server DNS address could not be found.

I'd be happy with less than 90degrees , any comments on 70degrees are fine. It's a basic common- sense matter but it's for explaining drag resistance to academics who think that sharpness is the only factor , and width , area and material densities have no meaning. The sort of people who say boats can't be made of iron as it sinks. ( Titanic had a fire in the coal bunkers , it should have floated )

 

[lpdsn]

Thank you all. Amateur Y research says: This site can’t be reached
ourworld.compuserve.com’s server DNS address could not be found.

I'd be happy with less than 90degrees , any comments on 70degrees are fine. It's a basic common- sense matter but it's for explaining drag resistance to academics who think that sharpness is the only factor , and width , area and material densities have no meaning. The sort of people who say boats can't be made of iron as it sinks. ( Titanic had a fire in the coal bunkers , it should have floated )

If it is academically related probably your best bet is to get in touch with that Uni in Southampton that does yacht design courses. Southampton Solent Uni rather than the University of Southampton.

https://www.solent.ac.uk/courses/undergraduate/yacht-design-and-production-beng

 

[TLouth7]

I'd be happy with less than 90degrees , any comments on 70degrees are fine. It's a basic common- sense matter but it's for explaining drag resistance to academics who think that sharpness is the only factor , and width , area and material densities have no meaning. The sort of people who say boats can't be made of iron as it sinks. ( Titanic had a fire in the coal bunkers , it should have floated )

The equation for drag has both Area and Density terms in it, which ought to satisfy an academic that they are relevant.

I imagine that at very high angles of attack the foil profile (inc. thickness) is irrelevant, so you could just look at values of drag coefficient for a flat plate. Profile will affect the angle of stall, but have much less effect beyond that point.

I am sadly familiar with foils stalled conditions, but nothing quite like what you describe other than a hard broach, where heel effects will be highly relevant.