The Spoon trick

[jayt]

That's what makes an airplane fly too.

If you ever reasearch the topic you'll find that there is mixed consensus within the aeronautics community about that. Half the industry believes what we all were taught in school - that the higher velocity of the air on the top of a curved wing reduces the pressure, producing lift from the higher pressure air underneath.
However, the other half dispute this - see the NASA papers below. Clearly symetrical wings work very well on high performance aircraft, so a wing does not need to have a curved upper surface and a flat underside to produce lift. I'm not taking sides here, but everyone should know that the subject is much more complex than just Bernoulli. As far as sponson shape and water is concerned - theory is nice, but results on the water are what matter.

http://www.grc.nasa.gov/WWW/K-12/airplane/wrong1.html

http://www.grc.nasa.gov/WWW/K-12/airplane/bernnew.html

.

 

[Preston_Hall]

Before you guys waist too much time building "S" shaped sponsons and flat surfaced sponsons you should go read one of Marty Davis' papers on sponson design. If you are going to heat race then you will want some belly or you will just slap the water all day. Been there.

 

[Don Ferrette]

Before you guys waist too much time building "S" shaped sponsons and flat surfaced sponsons you should go read one of Marty Davis' papers on sponson design. If you are going to heat race then you will want some belly or you will just slap the water all day. Been there.

 

[Mike Larson]

In all actuality... I dont build much at all.... Thanks Rod for keeping me in my place..... it was the exact response Id had imagined..... and with other knowlegable guys jumping on the bandwagon too..... There was, though, innovative response, and Im grateful for that...Jay,... . Preston, thanks.... Ive spent years in the chase boat..... funny thing.... the hydros I built never kite........ hmmm.... new tunnel this winter?.... I think not........ you cats really rock, penalizing a novice for asking questions, stupid, or not! Ray Charles coulda probly felt the difference between a flat surface and spoon.......( My simple observation, was it seemed, that the faster the water ran, the quicker the spoon sucked into it) So, seeing how Im testing protos for a builder I know, and a **** good one at that, what flaws need to be addressed, what doesnt, or, seeing how the actual build is as innovative as said builder wants to instill into it, who cares? You will still row after tunnel hulls, after a thousand builds.... its the nature of the beast.... get used to it. THAT is the tunnel hull secret! Now, wheres that spellchecker thing on here? Such a nice day......... mike

 

[Dan_Cousin]

what if you sand the spoon to 600 grit??? :lol: :lol:

 

[anthony_marquart]

You know,.. almost every good thread ends up in something like this anymore... Is it "end of the season tension" or what,... It's really nice to have exerts on the forum guys,... but we are just running toy boats you know... lighten up,.. take it easy,... man I'm almost afraid to post anymore..

In all actuality... I dont build much at all.... Thanks Rod for keeping me in my place..... it was the exact response Id had imagined..... and with other knowlegable guys jumping on the bandwagon too..... There was, though, innovative response, and Im grateful for that...Jay,... . Preston, thanks.... Ive spent years in the chase boat..... funny thing.... the hydros I built never kite........ hmmm.... new tunnel this winter?.... I think not........ you cats really rock, penalizing a novice for asking questions, stupid, or not! Ray Charles coulda probly felt the difference between a flat surface and spoon.......( My simple observation, was it seemed, that the faster the water ran, the quicker the spoon sucked into it) So, seeing how Im testing protos for a builder I know, and a **** good one at that, what flaws need to be addressed, what doesnt, or, seeing how the actual build is as innovative as said builder wants to instill into it, who cares? You will still row after tunnel hulls, after a thousand builds.... its the nature of the beast.... get used to it. THAT is the tunnel hull secret! Now, wheres that spellchecker thing on here? Such a nice day......... mike

 

[PakMan]

"Before you guys waist too much time building "S" shaped sponsons and flat surfaced sponsons you should go read one of Marty Davis' papers on sponson design. If you are going to heat race then you will want some belly or you will just slap the water all day. Been there."

Thanks for teasin' us.... oh wise one, please list the links so we can learn.... or if you can, explain???

Thanks,

David

 

[jayt]

...Im grateful for that...Jay,... .

You are most welcome!
It's getting so that I'm almost afraid to post facts in a techjnical thread anymore - for fear that someone's pet myth will be exposed and they will get twisted out of shape.....

.

 

[Rich Z]

Bernoulli's principle states that in fluid flow, an increase in velocity occurs simultaneously with decrease in pressure. This principle is a simplification of Bernoulli's equation which states that the sum of all forms of energy in a fluid flowing along an enclosed path (a streamline) is the same at any two points in that path. It is named after the Dutch/Swiss mathematician/scientist Daniel Bernoulli, though it was previously understood by Leonhard Euler and others. In a fluid flow with no viscosity, and therefore one in which a pressure difference is the only accelerating force, it is equivalent to Newton's laws of motion. It is important to note that the only cause of the change in fluid velocity is the difference in pressures either side of it. It is very common for the Bernoulli effect to be quoted as if it states that a change in velocity causes a change in pressure. The Bernoulli principle does not make this statement and it is not the case.

Hint - Hint - oh wizened one's

We run or boats on the surface of the water - NOT THROUGH IT !!!!!!!

Well........... most of us anyway

 

[SayMikey]

Bernoulli's principle states that in fluid flow, an increase in velocity occurs simultaneously with decrease in pressure. This principle is a simplification of Bernoulli's equation which states that the sum of all forms of energy in a fluid flowing along an enclosed path (a streamline) is the same at any two points in that path. It is named after the Dutch/Swiss mathematician/scientist Daniel Bernoulli, though it was previously understood by Leonhard Euler and others. In a fluid flow with no viscosity, and therefore one in which a pressure difference is the only accelerating force, it is equivalent to Newton's laws of motion. It is important to note that the only cause of the change in fluid velocity is the difference in pressures either side of it. It is very common for the Bernoulli effect to be quoted as if it states that a change in velocity causes a change in pressure. The Bernoulli principle does not make this statement and it is not the case.

Hint - Hint - oh wizened one's

We run or boats on the surface of the water - NOT THROUGH IT !!!!!!!

Well........... most of us anyway

I never saw a spoon at the nats justa MIXA with a kick

 

[Charles Perdue]

OK, I follow this so far. Will someone explain to me how a marine propeller with a curve in it works in the water. Not trying to be a smart ass, I am just naturally curious.

 

[Ed.R]

OK, I follow this so far. Will someone explain to me how a marine propeller with a curve in it works in the water. Not trying to be a smart ass, I am just naturally curious.

Thats a good question I was wondering that myself but I have my hands full with spoons .

How come ya'll race clockwise and not counter clockwise ?

 

[Rick Cesati]

OK, I follow this so far. Will someone explain to me how a marine propeller with a curve in it works in the water. Not trying to be a smart ass, I am just naturally curious.

Thats a good question I was wondering that myself but I have my hands full with spoons .

How come ya'll race clockwise and not counter clockwise ?

As I understand it...the direction we race is opposite to propeller rotation. Torque, etc. I'm sure someone can elaborate.

Rick

 

[Preston_Hall]

Thanks for teasin' us.... oh wise one, please list the links so we can learn.... or if you can, explain???

Good Info here RCBOAT.COM

Look in the Technical Papers. I could not find it specifically but Marty is a member here and maybe he will chime in or you can contact him.

You know,.. almost every good thread ends up in something like this anymore... Is it "end of the season tension" or what,... It's really nice to have exerts on the forum guys,... but we are just running toy boats you know... lighten up,.. take it easy,... man I'm almost afraid to post anymore..

What in the world are you talking about?

We run or boats on the surface of the water - NOT THROUGH IT !!!!!!!

That's kind of been my take on the situation. In my experinces, it seems "blowing off the water" is due mostly to sponson design.

 

[Jerry Wyss]

Before you guys waist too much time building "S" shaped sponsons and flat surfaced sponsons you should go read one of Marty Davis' papers on sponson design. If you are going to heat race then you will want some {belly} or you will just slap the water all day. Been there.

There's That Word, "belly",, I know I'm in the wrong forum but the Lynx has a very distinct

"belly" and that boat corners like a razor. I knew that was the right word,, carry on

 

[Geraghty]

There's That Word, "belly",, I know I'm in the wrong forum but the Lynx has a very distinct

"belly" and that boat corners like a razor. I knew that was the right word,, carry on

"Tunnel boat" sponsons,by design and definition,have a "belly" in their sponsons.That is why "good linear user friendly" handling tunnel boats need stumble blocks.

Take the stumble blocks off your LYNX and see what you have.I guarantee you will be rowing after it "all"

day long.Carl wouldn't have them on the boat if he didn't need them.

It was the post about tunnel boats hooking in the outboard forum that started all this again.

What I was trying to explain was how to stop tunnelboats from hooking,hydros from nose steering and monos from spinning out.It is obvious that ......ah to hell with it.........

I apologize for taking up this forums space.I should be hit in the head with a #@*^%$ shovel for even bringing the subject up. :angry:

 

[Bart Drieghe]

Rod , Don't put your head in the ground . Its always good to hear someones theory or experience . But , like you'll have noticed , some will apply your experience , some will throw it in the bin .

Regards ,

B

 

[Mike Hughes]

Bang!!! Upside the head with a shovel.

 

[Ed.R]

There's That Word, "belly",, I know I'm in the wrong forum but the Lynx has a very distinct

"belly" and that boat corners like a razor. I knew that was the right word,, carry on

"Tunnel boat" sponsons,by design and definition,have a "belly" in their sponsons.That is why "good linear user friendly" handling tunnel boats need stumble blocks.

Take the stumble blocks off your LYNX and see what you have.I guarantee you will be rowing after it "all"

day long.Carl wouldn't have them on the boat if he didn't need them.

It was the post about tunnel boats hooking in the outboard forum that started all this again.

What I was trying to explain was how to stop tunnelboats from hooking,hydros from nose steering and monos from spinning out.It is obvious that ......ah to hell with it.........

I apologize for taking up this forums space.I should be hit in the head with a #@*^%$ shovel for even bringing the subject up. :angry:

Don't worry Rod , I enjoy when people bring up ideas that WON and still WIN I don't care what some of these people say . I'm sure there more experianced and knowledgeable than most anyway .

LIGHTEN the HELL up PEOPLE !!!!!

TOY BOATS !!!!!!!!!!

 

[Jerry Wyss]

Well that went a little sideway's, it's probably my fault,, I was using that word "belly" a while

back in another forum topic, not really knowing if it was the correct term.

When Preston used that word it got my attention and I interjected prolly when I shouldn't,,

I like that word "prolly" too,, No worries mates h34r: