On Mon, 30 Aug 2004 07:33:32 -0400, DSK wrote:

More power = more speed.

This has an asymptotical limit, though.

JAXAshby wrote:
you don't know squat about the shape of the power curve of a boat at or
anywhere near hull speed.

JAXAshby wrote:
as·ymp·tote ( P ) Pronunciation Key (sm-tt, -mp-)
n.
A line whose distance to a given curve tends to zero. An asymptote may or may
not intersect its associated curve

And you're saying that the power curve of a boat "at or near hull speed"
does not have an asymptote?

I am puzzled. What quantity approaches an asymptote and against what
independent variable?


Rodney Myrvaagnes NYC


We have achieved faith-based science,
faith-based economics, faith-based law
enforcement, and faith-based missile
defense.
What's next? Faith-based air traffic control?

On Mon, 30 Aug 2004 18:00:32 -0400, Rodney Myrvaagnes
wrote:

On Mon, 30 Aug 2004 07:33:32 -0400, DSK wrote:

More power = more speed.

This has an asymptotical limit, though.
//
I am puzzled. What quantity approaches an asymptote and against what
independent variable?


Rodney Myrvaagnes NYC


Comments from the lunatic fringe aside: if one plots power versus
water speed for any water borne hull there is an upper limit to speed
no matter HOW much power is applied to the hull.

(motive power is ultimately limited by flotation. Speed is ultimately
limited by propeller immersion or hull stability)

Brian Whatcott

Any Naval Architect would agree to your statement.

brian, please stay quiet. That way no one will realize you learned everything
there is to know about science from a year's subscription to Popular Mechanix.

From: Brian Whatcott
Date: 8/30/2004 6:48 PM Eastern Daylight Time
Message-id:

On Mon, 30 Aug 2004 18:00:32 -0400, Rodney Myrvaagnes
wrote:

On Mon, 30 Aug 2004 07:33:32 -0400, DSK wrote:

More power = more speed.

This has an asymptotical limit, though.
//
I am puzzled. What quantity approaches an asymptote and against what
independent variable?


Rodney Myrvaagnes NYC


Comments from the lunatic fringe aside: if one plots power versus
water speed for any water borne hull there is an upper limit to speed
no matter HOW much power is applied to the hull.

(motive power is ultimately limited by flotation. Speed is ultimately
limited by propeller immersion or hull stability)

Brian Whatcott

On Mon, 30 Aug 2004 22:48:22 GMT, Brian Whatcott
wrote:

On Mon, 30 Aug 2004 18:00:32 -0400, Rodney Myrvaagnes
wrote:

On Mon, 30 Aug 2004 07:33:32 -0400, DSK wrote:

More power = more speed.

This has an asymptotical limit, though.
//
I am puzzled. What quantity approaches an asymptote and against what
independent variable?


Rodney Myrvaagnes NYC


Comments from the lunatic fringe aside: if one plots power versus
water speed for any water borne hull there is an upper limit to speed
no matter HOW much power is applied to the hull.

(motive power is ultimately limited by flotation. Speed is ultimately
limited by propeller immersion or hull stability)

Count me as lunatic fringe. I see planing boats every day.

What you describe is not an asymptotic relation.

Rodney Myrvaagnes J36 Gjo/a


Let us restore integrity and honor to the White House

Rodney Myrvaagnes wrote:
Count me as lunatic fringe. I see planing boats every day.

Planing boats have the same limit, in other words as they go faster,
each incremental increase in speed takes an increasing increment in
power. Eventually the power/speed curve gets just as steep as
displacement hulls...


What you describe is not an asymptotic relation.

?

Looks like it to me. It's just much farther to the right on the graph

Fresh Breezes- Doug King

On Tue, 31 Aug 2004 12:42:04 -0400, DSK wrote:

Rodney Myrvaagnes wrote:
Count me as lunatic fringe. I see planing boats every day.

Planing boats have the same limit, in other words as they go faster,
each incremental increase in speed takes an increasing increment in
power. Eventually the power/speed curve gets just as steep as
displacement hulls...


What you describe is not an asymptotic relation.

?

Looks like it to me. It's just much farther to the right on the graph

In neither case does it get vertical, as an asymptote would.

In the case of planing boats, the slope of the curve doesn't even
increase everywhere, buty goes over a hump at the onset of planing.

But ordinary medium-to-light-displacement sailboats zip right past
hull speed when the wind rises.


Rodney Myrvaagnes J36 Gjo/a


Let us restore integrity and honor to the White House

Looks like it to me. It's just much farther to the right on the graph


Rodney Myrvaagnes wrote:
In neither case does it get vertical, as an asymptote would.

1- an asymptote doesn't have to be vertical (or horizontal) on the graph

2- if the power/speed curve does not go vertical (or approach it very
very very closely) then you're saying that the boat can reach infinite
speed. This is impossible, nyet?


In the case of planing boats, the slope of the curve doesn't even
increase everywhere, buty goes over a hump at the onset of planing.

Depends on the boat. Some don't have much of a hump at all.

"Hump" is kind of a misnomer IMHO... what happens is that the boat's
power/speed curve trends increasingly upward as marginal power increases
faster than speed, then flattens out again as it starts planing. It's
not a hump, more of a plateau or shelf.


But ordinary medium-to-light-displacement sailboats zip right past
hull speed when the wind rises.

Do they reach infinite speed?

You're right about fast boats zipping right past hull speed like it's
not there... that's why I always say that "hull speed" is not a hard
limit... also you have to consider the speed-length ratio (or Froude
number if you prefer) is not the same for all boats. Two different boats
(say, a J-35 and an Island Packet 35) should not really have the same
"hull speed" even if their LWL is exactly the same.

The power/speed curve of all boats... power, sail, diplacement, planing,
mulithull, whatever... trends toward vertical as the speed increases.
For some boats it's way to the right, at impressively high speeds. But
it's there!

Fresh Breezes- Doug King

You are using "asymptote" in a metaphoric, rather than mathematical
sense.



On Tue, 31 Aug 2004 13:31:46 -0400, DSK wrote:

Looks like it to me. It's just much farther to the right on the graph


Rodney Myrvaagnes wrote:
In neither case does it get vertical, as an asymptote would.

1- an asymptote doesn't have to be vertical (or horizontal) on the graph

2- if the power/speed curve does not go vertical (or approach it very
very very closely) then you're saying that the boat can reach infinite
speed. This is impossible, nyet?


In the case of planing boats, the slope of the curve doesn't even
increase everywhere, buty goes over a hump at the onset of planing.

Depends on the boat. Some don't have much of a hump at all.

"Hump" is kind of a misnomer IMHO... what happens is that the boat's
power/speed curve trends increasingly upward as marginal power increases
faster than speed, then flattens out again as it starts planing. It's
not a hump, more of a plateau or shelf.


But ordinary medium-to-light-displacement sailboats zip right past
hull speed when the wind rises.

Do they reach infinite speed?

You're right about fast boats zipping right past hull speed like it's
not there... that's why I always say that "hull speed" is not a hard
limit... also you have to consider the speed-length ratio (or Froude
number if you prefer) is not the same for all boats. Two different boats
(say, a J-35 and an Island Packet 35) should not really have the same
"hull speed" even if their LWL is exactly the same.

The power/speed curve of all boats... power, sail, diplacement, planing,
mulithull, whatever... trends toward vertical as the speed increases.
For some boats it's way to the right, at impressively high speeds. But
it's there!

Fresh Breezes- Doug King


Rodney Myrvaagnes NYC J36 Gjo/a

"Religious wisdom is to wisdom as military music is to music."

1- an asymptote doesn't have to be vertical (or horizontal) on the graph

huh?