|
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." |
I've really resisted jumping into this one, but....
I guess that if you consider VERY high speeds (approaching the speed of light), it does go asymptotic. However, at anything significantly below that, to suggest that there is some "brick wall" velocity that cannot be surpassed no matter how much thrust is applied is just plain incorrect. Now, the thrust required may not be achievable by any normal engineering and forces on the hull may cause any it to disintegrate if built out of any of the standard materials and methods. And even if you could build it strong enough, stability and control problems will rear their ugly heads when you start going fast enough. Afterall, if you could keep it from pitch poling first, and pushed my Tayana fast enough, you'd get seperation occuring with the water flow where my hull starts curving back to the stern. Once the rudder is high and dry in this seperation area, it'd be a might difficult to control. So in the real world, I guess that there is a limit to how fast my Tayana can go no matter how many JATO units you strap onto it. But it is a pratical matter, not some theoretical "hull speed" value beyond which the resistance somehow becomes infinite. A quick thought experiment to show the point: Picture yourself speeding along on glassy smooth water in a speed boat. You have a small model of a displacement hull sailboat in your hand (only a few inches long). Now, since the hull speed of this model is only a fraction of a knot, if there were a hard and fast limit beyound which it is impossible to go, then you could not reach over the side and drag this toy through the water. It would wrench your arm off. If you had it somehow affixed to the boat, it would stop the speed boat cold. Can we find something else to agrue about now? Rodney Myrvaagnes wrote: 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." -- Dan Best - (707) 431-1662, Healdsburg, CA 95448 B-2/75 1977-1979 Tayana 37 #192, "Tricia Jean" http://rangerbest.home.comcast.net/TriciaJean.JPG |
On Tue, 31 Aug 2004 00:22:00 -0400, Rodney Myrvaagnes
wrote: 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 Hmmm...you feel that if a boat planes, then it has no upper speed limit? 100 mph? 500 mph? 1000 mph? And if you wish a planing hull to go faster, you merely fit a more powerful engine: 100 HP? 1000 HP?? 10,000 HP??? 100,000 HP???? If on further consideration, you might allow that there is SOME upper power and speed for a given hull, then perhaps you might even describe the relation as asymptotic? I hold that the situation I describe, though fanciful, is aptly called asymptotic. Telling me that my description is not asymptotic as I describe it, is called an assertion "Ex Cathedra". How are your ecclesiastical affiliations? :-) Brian Whatcott Altus OK |
On Tue, 31 Aug 2004 17:01:57 -0400, Rodney Myrvaagnes
wrote: You are using "asymptote" in a metaphoric, rather than mathematical sense. Hah, another bald statement of what's right and what's wrong: let's go for some clarifications: [lifted from a math site] Definition of a horizontal asymptote: The line y = y0 is a "horizontal asymptote" of f(x) if and only if f(x) approaches y0 as x approaches + or - inf Definition of a vertical asymptote: The line x = x0 is a "vertical asymptote" of f(x) if and only if f(x) approaches + or - inf as x approaches x0 from the left or from the right. Definition of a slant asymptote: the line y = ax + b is a "slant asymptote" of f(x) if and only if lim (x--+/-) f(x) = ax + b. ************************************************** ******************* Does this clarify your thoughts on what is and is not asymptotic? :-) Brian W |
Rodney Myrvaagnes wrote:
You are using "asymptote" in a metaphoric, rather than mathematical sense. Not at all. Some realistic numbers, for example: Let's say 1 horsepower (applied) will drive a given boat 4 knots. 2 horsepower will drive it 5.5 knots 3 horsepower will drive it 6.7 4 horsepower will drive it 7.5 6 horsepower will drive it 8.1 8 horsepower will drive it 8.5 12 horsepower will drive it 8.7 20 horsepower will drive it 8.8 50 horsepower will drive it 8.85 Now, is this a boat capable of planing? If yes, then we'll see an increase in the amount increased speed for the next increase in horsepower... then the trend will reappear. Next thing you know, each increased bit of speed, down to hundredths of knot increments, require many hundreds of horsepower to attain. Is this asymptotic enough for you? No? Okay, let's keep going... we have hypothetically infinite horsepower ;) If we were adding millions of horsepower for each hundredth of a knot increase in speed, is *that* asymptotic enough for you? No? How far do we continue this trend? We're inventing new universes to contain the number of added horsepower for each increased femto-knot. For the last umptysquintillion trillion horsepower we've added, we have not seen a 1/8 knot increase.... Let me guess, you don't consider that asymptotic? I would, and so would most mathematicians & most yacht designers. YMMV Fresh Breezes- Doug King |
dougies, knock it off. you are not even attempting to fool newbees any more.
too much alcohol or age or DGAF. From: DSK Date: 8/31/2004 12:42 PM Eastern Daylight Time Message-id: 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 |
Rod, you are arguing with dougies and dougies don't care what you say. dougies
only cares what dougies says. 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 |
1- an asymptote doesn't have to be vertical (or horizontal) on the graph
huh? |
You are using "asymptote" in a metaphoric, rather than mathematical
sense. dougies doesn't know the difference. dougies sells concrete slabs to first time single wide trailer buyers for a living. dougies thinks that makes him a scientific genius. |
Dan, don't confuse them with facts. they are their minds (such as their minds
are) made up. I've really resisted jumping into this one, but.... I guess that if you consider VERY high speeds (approaching the speed of light), it does go asymptotic. However, at anything significantly below that, to suggest that there is some "brick wall" velocity that cannot be surpassed no matter how much thrust is applied is just plain incorrect. Now, the thrust required may not be achievable by any normal engineering and forces on the hull may cause any it to disintegrate if built out of any of the standard materials and methods. And even if you could build it strong enough, stability and control problems will rear their ugly heads when you start going fast enough. Afterall, if you could keep it from pitch poling first, and pushed my Tayana fast enough, you'd get seperation occuring with the water flow where my hull starts curving back to the stern. Once the rudder is high and dry in this seperation area, it'd be a might difficult to control. So in the real world, I guess that there is a limit to how fast my Tayana can go no matter how many JATO units you strap onto it. But it is a pratical matter, not some theoretical "hull speed" value beyond which the resistance somehow becomes infinite. A quick thought experiment to show the point: Picture yourself speeding along on glassy smooth water in a speed boat. You have a small model of a displacement hull sailboat in your hand (only a few inches long). Now, since the hull speed of this model is only a fraction of a knot, if there were a hard and fast limit beyound which it is impossible to go, then you could not reach over the side and drag this toy through the water. It would wrench your arm off. If you had it somehow affixed to the boat, it would stop the speed boat cold. Can we find something else to agrue about now? Rodney Myrvaagnes wrote: 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." -- Dan Best - (707) 431-1662, Healdsburg, CA 95448 B-2/75 1977-1979 Tayana 37 #192, "Tricia Jean" http://rangerbest.home.comcast.net/TriciaJean.JPG |
If on further consideration, you might allow that there is SOME upper
power and speed for a given hull, then perhaps you might even describe the relation as asymptotic? sorry, brian, that is not what the word "asymptotic" means. And **certainly** the "professor" (if he were not bogus) who used the word would indeed know what it means. |
brian, obviously it did not clarify yours.
that is what happens when one expects a 10 second sound bite from CNN and/or Google to bring universal enlightenment. You are using "asymptote" in a metaphoric, rather than mathematical sense. Hah, another bald statement of what's right and what's wrong: let's go for some clarifications: [lifted from a math site] Definition of a horizontal asymptote: The line y = y0 is a "horizontal asymptote" of f(x) if and only if f(x) approaches y0 as x approaches + or - inf Definition of a vertical asymptote: The line x = x0 is a "vertical asymptote" of f(x) if and only if f(x) approaches + or - inf as x approaches x0 from the left or from the right. Definition of a slant asymptote: the line y = ax + b is a "slant asymptote" of f(x) if and only if lim (x--+/-) f(x) = ax + b. ************************************************* ******************** Does this clarify your thoughts on what is and is not asymptotic? :-) Brian W |
dougies, PLAINLY you don't have a clew what the word "asymptote" means.
PLAINLY. Now, KINDLY knock it off. You are using "asymptote" in a metaphoric, rather than mathematical sense. Not at all. Some realistic numbers, for example: Let's say 1 horsepower (applied) will drive a given boat 4 knots. 2 horsepower will drive it 5.5 knots 3 horsepower will drive it 6.7 4 horsepower will drive it 7.5 6 horsepower will drive it 8.1 8 horsepower will drive it 8.5 12 horsepower will drive it 8.7 20 horsepower will drive it 8.8 50 horsepower will drive it 8.85 Now, is this a boat capable of planing? If yes, then we'll see an increase in the amount increased speed for the next increase in horsepower... then the trend will reappear. Next thing you know, each increased bit of speed, down to hundredths of knot increments, require many hundreds of horsepower to attain. Is this asymptotic enough for you? No? Okay, let's keep going... we have hypothetically infinite horsepower ;) If we were adding millions of horsepower for each hundredth of a knot increase in speed, is *that* asymptotic enough for you? No? How far do we continue this trend? We're inventing new universes to contain the number of added horsepower for each increased femto-knot. For the last umptysquintillion trillion horsepower we've added, we have not seen a 1/8 knot increase.... Let me guess, you don't consider that asymptotic? I would, and so would most mathematicians & most yacht designers. YMMV Fresh Breezes- Doug King |
On Tue, 31 Aug 2004 22:45:18 GMT, Brian Whatcott
wrote: On Tue, 31 Aug 2004 00:22:00 -0400, Rodney Myrvaagnes wrote: 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 Hmmm...you feel that if a boat planes, then it has no upper speed limit? 100 mph? 500 mph? 1000 mph? And if you wish a planing hull to go faster, you merely fit a more powerful engine: 100 HP? 1000 HP?? 10,000 HP??? 100,000 HP???? For any equilibrium speed, if you add thrust it will go faster, unless it falls apart. I didn't say anything about how the thrust is applied. If on further consideration, you might allow that there is SOME upper power and speed for a given hull, then perhaps you might even describe the relation as asymptotic? No. Unless you can show an asymptotic function (mathematical) that describes the situation. I hold that the situation I describe, though fanciful, is aptly called asymptotic. Telling me that my description is not asymptotic as I describe it, is called an assertion "Ex Cathedra". How are your ecclesiastical affiliations? You may consider it an apt metaphor. I consider it a rather vague one. In any case it is only a metaphor. :-) Brian Whatcott Altus OK Rodney Myrvaagnes NYC J36 Gjo/a "Religious wisdom is to wisdom as military music is to music." |
On Tue, 31 Aug 2004 22:55:08 GMT, Brian Whatcott
wrote: On Tue, 31 Aug 2004 17:01:57 -0400, Rodney Myrvaagnes wrote: You are using "asymptote" in a metaphoric, rather than mathematical sense. Hah, another bald statement of what's right and what's wrong: let's go for some clarifications: [lifted from a math site] Definition of a horizontal asymptote: The line y = y0 is a "horizontal asymptote" of f(x) if and only if f(x) approaches y0 as x approaches + or - inf Definition of a vertical asymptote: The line x = x0 is a "vertical asymptote" of f(x) if and only if f(x) approaches + or - inf as x approaches x0 from the left or from the right. Definition of a slant asymptote: the line y = ax + b is a "slant asymptote" of f(x) if and only if lim (x--+/-) f(x) = ax + b. ************************************************* ******************** Does this clarify your thoughts on what is and is not asymptotic? No, because I already knew what it was. :-) Brian W Rodney Myrvaagnes NYC J36 Gjo/a "Religious wisdom is to wisdom as military music is to music." |
"DSK" wrote in message
... Rodney Myrvaagnes wrote: You are using "asymptote" in a metaphoric, rather than mathematical sense. Not at all. Some realistic numbers, for example: Let's say 1 horsepower (applied) will drive a given boat 4 knots. 2 horsepower will drive it 5.5 knots 3 horsepower will drive it 6.7 4 horsepower will drive it 7.5 6 horsepower will drive it 8.1 8 horsepower will drive it 8.5 12 horsepower will drive it 8.7 20 horsepower will drive it 8.8 50 horsepower will drive it 8.85 Now, is this a boat capable of planing? If yes, then we'll see an increase in the amount increased speed for the next increase in horsepower... then the trend will reappear. These figures are not realistic. Up to the point of the hull speed they resemble reality, but as soon as the hull starts planing, more 'ordinary' rules of resistance/drag apply and as far as I know the function becomes more like a square root function, which is mathematically definately not an asymptote. Meindert |
the function becomes
more like a square root function, which is mathematically definately not an asymptote. Meindert watch it, Meindert. dougies is now going to spend two days and five posts trying to show *you* are wrong when you say a square function is no asymptotic. |
Meindert Sprang wrote:
These figures are not realistic. Up to the point of the hull speed they resemble reality, but as soon as the hull starts planing, more 'ordinary' rules of resistance/drag apply and as far as I know the function becomes more like a square root function, which is mathematically definately not an asymptote. Well, there's your mistake. A hull under planing conditions is subject to normal drag, including air resistance. It no longer is subject to wave-making resistance, but that doesn't mean that *all* resistance goes away. And the function for increase is a multiple of velocity squared, which will have an asymptote. DSK |
"DSK" wrote in message
.. . Well, there's your mistake. A hull under planing conditions is subject to normal drag, including air resistance. It no longer is subject to wave-making resistance, but that doesn't mean that *all* resistance goes away. And the function for increase is a multiple of velocity squared, which will have an asymptote. Ok, I'm going to argue this one only once: by mathematical definition, a squared function is NOT asymptotic. Because, as you can read in any mathematics book, an asymptote reaches infinity on one axis for a defined value on the other axis, while a squared function can reach infinity on both axes. Meindert PS: thanks for the warning Jax but he was quicker than you thought.....:-) |
Meindert Sprang wrote:
Ok, I'm going to argue this one only once: by mathematical definition, a squared function is NOT asymptotic. Because, as you can read in any mathematics book, an asymptote reaches infinity on one axis for a defined value on the other axis, while a squared function can reach infinity on both axes. Oh, OK. I see now... Please explain further... the power/speed graph can reach infinity on both axes? Does this mean that we can have negative horsepower? That would make for excellent fuel efficiency! DSK |
"DSK" wrote in message
... Meindert Sprang wrote: Ok, I'm going to argue this one only once: by mathematical definition, a squared function is NOT asymptotic. Because, as you can read in any mathematics book, an asymptote reaches infinity on one axis for a defined value on the other axis, while a squared function can reach infinity on both axes. Oh, OK. I see now... Please explain further... the power/speed graph can reach infinity on both axes? Does this mean that we can have negative horsepower? That would make for excellent fuel efficiency! Sigh! With both axes I mean X and Y axis. And in our case only in the first quadrant, where X and Y are positive. Meindert |
Please explain further... the power/speed graph can reach infinity on
both axes? Does this mean that we can have negative horsepower? That would make for excellent fuel efficiency! Meindert Sprang wrote: Sigh! With both axes I mean X and Y axis. And in our case only in the first quadrant, where X and Y are positive. Dammit, another great idea shot down... I thought we could have a boat where if you put the engine in gear while you were sailing, it would actually *produce* fuel. Anyway, the power/speed curve will "approach infinity" much much much sooner along the power axis (usually Y) than the speed axis (usually X). That's the whole point. Fresh Breezes Doug King |
On Wed, 01 Sep 2004 00:32:59 -0400, Rodney Myrvaagnes
wrote: I am puzzled. What quantity approaches an asymptote and against what independent variable? Rodney Myrvaagnes NYC Count me as lunatic fringe. I see planing boats every day. What you describe is not an asymptotic relation. Rodney Myrvaagnes J36 Gjo/a I hold that the situation I describe, though fanciful, is aptly called asymptotic. Telling me that my description is not asymptotic as I describe it, is called an assertion "Ex Cathedra". How are your ecclesiastical affiliations? // If on further consideration, you might allow that there is SOME upper power and speed for a given hull, then perhaps you might even describe the relation as asymptotic? Brian Whatcott Altus OK No. Unless you can show an asymptotic function (mathematical) that describes the situation. /// In any case it is only a metaphor. Rodney Myrvaagnes NYC J36 Gjo/a Let me rise to the challenge, and hopefully demetaphoricate this mathematical concept a little more for you with a worked example, as given at the following URL http://www.purplemath.com/modules/asymtote4.htm Take a look at the third worked example on this page, it carries a numerator in the second power, and a denominator in the first power. This is somewhat like a practical thrust versus speed relation for a hull. You will notice there may be a vertical asymptote, a slant asymptote or a horizontal asymptote (though not both the latter, obviously) Hope this helps? It may also be responsive to Meindert's view [below]: Meindert Sprang wrote: Ok, I'm going to argue this one only once: by mathematical definition, a squared function is NOT asymptotic. Because, as you can read in any mathematics book, an asymptote reaches infinity on one axis for a defined value on the other axis, while a squared function can reach infinity on both axes. Brian Whatcott Altus OK |
Meindert, you confuse dougies so with facts.
Well, there's your mistake. A hull under planing conditions is subject to normal drag, including air resistance. It no longer is subject to wave-making resistance, but that doesn't mean that *all* resistance goes away. And the function for increase is a multiple of velocity squared, which will have an asymptote. Ok, I'm going to argue this one only once: by mathematical definition, a squared function is NOT asymptotic. Because, as you can read in any mathematics book, an asymptote reaches infinity on one axis for a defined value on the other axis, while a squared function can reach infinity on both axes. Meindert PS: thanks for the warning Jax but he was quicker than you thought.....:-) |
give it up, dogies. you are
sooooooooooooooooooooooooooooooooooooooooooooooooo oooooooooooooooooooooooo oooooooooooooooooooooooooooooooooooo far behind the power curve you can never recover. pity that you do not now and never will understand that. From: DSK Date: 9/1/2004 12:26 PM Eastern Daylight Time Message-id: Meindert Sprang wrote: Ok, I'm going to argue this one only once: by mathematical definition, a squared function is NOT asymptotic. Because, as you can read in any mathematics book, an asymptote reaches infinity on one axis for a defined value on the other axis, while a squared function can reach infinity on both axes. Oh, OK. I see now... Please explain further... the power/speed graph can reach infinity on both axes? Does this mean that we can have negative horsepower? That would make for excellent fuel efficiency! DSK |
Meindert, dougies will argue on and on and on and on and on and on hoping you
forget what you originally said. dougiees is one dumb squat pretending to be human. Meindert Sprang wrote: Ok, I'm going to argue this one only once: by mathematical definition, a squared function is NOT asymptotic. Because, as you can read in any mathematics book, an asymptote reaches infinity on one axis for a defined value on the other axis, while a squared function can reach infinity on both axes. Oh, OK. I see now... Please explain further... the power/speed graph can reach infinity on both axes? Does this mean that we can have negative horsepower? That would make for excellent fuel efficiency! Sigh! With both axes I mean X and Y axis. And in our case only in the first quadrant, where X and Y are positive. Meindert |
|
yeah, sure. anything you say.
Date: 9/1/2004 6:20 PM Eastern Daylight Time Message-id: On Wed, 01 Sep 2004 14:55:48 -0400, DSK wrote: Please explain further... the power/speed graph can reach infinity on both axes? Does this mean that we can have negative horsepower? That would make for excellent fuel efficiency! Meindert Sprang wrote: Sigh! With both axes I mean X and Y axis. And in our case only in the first quadrant, where X and Y are positive. Dammit, another great idea shot down... I thought we could have a boat where if you put the engine in gear while you were sailing, it would actually *produce* fuel. Actually, it's a reality. There are now electric aux motors that can recharge battery banks by putting the drive in gear while sailing. Just one more thing about boats you don't know. I'm a little surprised about this one, because I'm sure it's been mentioned in the magazines where you get most of your "knowlege" BB |
|
On Wed, 01 Sep 2004 23:09:41 GMT, Brian Whatcott
wrote: On Wed, 01 Sep 2004 00:32:59 -0400, Rodney Myrvaagnes wrote: I am puzzled. What quantity approaches an asymptote and against what independent variable? Rodney Myrvaagnes NYC Count me as lunatic fringe. I see planing boats every day. What you describe is not an asymptotic relation. Rodney Myrvaagnes J36 Gjo/a I hold that the situation I describe, though fanciful, is aptly called asymptotic. Telling me that my description is not asymptotic as I describe it, is called an assertion "Ex Cathedra". How are your ecclesiastical affiliations? // If on further consideration, you might allow that there is SOME upper power and speed for a given hull, then perhaps you might even describe the relation as asymptotic? Brian Whatcott Altus OK No. Unless you can show an asymptotic function (mathematical) that describes the situation. /// In any case it is only a metaphor. Rodney Myrvaagnes NYC J36 Gjo/a Let me rise to the challenge, and hopefully demetaphoricate this mathematical concept a little more for you with a worked example, as given at the following URL http://www.purplemath.com/modules/asymtote4.htm Take a look at the third worked example on this page, it carries a numerator in the second power, and a denominator in the first power. This is somewhat like a practical thrust versus speed relation for a hull. You will notice there may be a vertical asymptote, a slant asymptote or a horizontal asymptote (though not both the latter, obviously) "May be?" If there is an asymptote there is no maybe about it. It is in the function. Hope this helps? It may also be responsive to Meindert's view [below]: Meindert Sprang wrote: Ok, I'm going to argue this one only once: by mathematical definition, a squared function is NOT asymptotic. Because, as you can read in any mathematics book, an asymptote reaches infinity on one axis for a defined value on the other axis, while a squared function can reach infinity on both axes. Brian Whatcott Altus OK Rodney Myrvaagnes NYC J36 Gjo/a "WooWooism lives" Anon grafitto on the base of the Cuttyhunk breakwater light |
On Wed, 01 Sep 2004 23:39:16 -0400, Rodney Myrvaagnes
wrote: /// Count me as lunatic fringe. /// Rodney Myrvaagnes J36 Gjo/a OK |
blarney bill, this thread has turned towards a discussion of what constitutes
an asymptote and its potential use in describing the speed of a boat through water, while *you* are babbling on about electric motors for small sailboat. bb? maybe you want to ask your doctor for some Ritlin? Date: 9/2/2004 6:40 AM Eastern Daylight Time Message-id: On 02 Sep 2004 02:32:36 GMT, (JAXAshby) wrote: yeah, sure. anything you say. Google it like you do everything else, jackax. There has been enough written about it, that even you could find it if you look. There are now even a few production sailboats that can be ordered with an optional electric aux motor. BB Date: 9/1/2004 6:20 PM Eastern Daylight Time Message-id: On Wed, 01 Sep 2004 14:55:48 -0400, DSK wrote: Please explain further... the power/speed graph can reach infinity on both axes? Does this mean that we can have negative horsepower? That would make for excellent fuel efficiency! Meindert Sprang wrote: Sigh! With both axes I mean X and Y axis. And in our case only in the first quadrant, where X and Y are positive. Dammit, another great idea shot down... I thought we could have a boat where if you put the engine in gear while you were sailing, it would actually *produce* fuel. Actually, it's a reality. There are now electric aux motors that can recharge battery banks by putting the drive in gear while sailing. Just one more thing about boats you don't know. I'm a little surprised about this one, because I'm sure it's been mentioned in the magazines where you get most of your "knowlege" BB |
"May be?" If there is an asymptote there is no maybe about it. It is
in the function. Rodney, don't confuse 'em with science. it gives 'em headaches. |
On Tue, 31 Aug 2004 21:46:31 GMT, Dan Best wrote:
I've really resisted jumping into this one, but.... This weekend in Olympia, Washington State, is the Harbor Days festival. During Harbor Days are the well-known tug boat races. As a sailor, I understand bow waves, hull speeds, and displacement hulls. It is a pretty good bet that the 70' tug will beat the 35' tug. I think the longer tug could win with the engine just above an idle. But it is really amazing to watch the bow wave dynamics in action. A 30 foot tug with 600 horsepower can build a HUGE bow wave and still not pass its hull speed. The waves generated in this race are far greater than the waves from cargo ships that are 10 times as long and 1,000 times larger. |
|
| All times are GMT +1. The time now is 12:18 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com