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how a sail works, who can help me explain?
The_navigatorŠ wrote in message ...
Where do you get these ideas? Of course energy conservation laws consider (and implicitly include) friction losses, compression and turbulence. Now just because you are familiar with *one* form of the Bernouille equation does not mean that is the only form. It is possible to derive forms for any set of integral boundary conditions with the proviso that you follow a streamline for continuity. Finally, although you seem to have missed it, the Bernoulli equation expressly considers compression of a fluid. -it comes into the density term(s). As I said, we understand how a sail works but you seem to be struggling. Cheers MC Leonard Eulers so called "Bernoulli equation" is the 1D (one dimensional case) of his 3D equations for an non existing, mathematical modeled fluid! Bernoulli equation is the integralform of Newton second law F=m*a! It is easier to show the direction of the Lifting Force using Newton´s second law directly. Many books explain Lift with the so called "Bernoulli effect", which means that " high airflow velocity causes low airpressure"! Professor Dooley shows here below that this is wrong: According to Professor Dooley, Millerville University, it will take one generation to understand Bernoulli equation and that " high velocity does not causes low pressure". http://muweb.millersv.edu/~jdooley/m...erap/eulap.htm Professor Dooyley writes down the page: "One confusing detail about Bernoulli's equation needs discussion: In elementary treatments it is often stated that, because of Bernoulli's equation, high velocity causes low pressure. This is like saying that the high velocity of bullet leaving a gun caused the low pressure of the gas outside the barrel of the gun. The field treatment embodied in Euler's and Bernoulli's equations does not discuss cause and effect. The field view tells us what parameters "go together" without implying that one causes the other. If we trace back to the roots of these equations in Newton's laws, we can extract a cause and effect statement: Forces are said to cause accelerations. In the same sense, pressure gradients cause changes in velocity; not the other way around." In real aerodynamic books one never finds the expression "Bernoulli Effect"! Wings of all new airliners are almost flat on upper surface! That´s called "Supercritical Wings" and they save their operators (as example airbus340 ) some 15 % over older aircrafts (Boeing 747-400)! http://aerodyn.org/HighSpeed/supercritical.html They now have longer airflow path below the wing compared to to upper surface! Some Professors explains Lift with "The Circulation Theory"! But Potential Theory and it´s correction, the superpositioned "Circulation Field" is not reality, only a mathematical model! Jan-Olov Newborg |
how a sail works, who can help me explain?
Jan-Olov Newborg wrote: The_navigatorŠ wrote in message ... Where do you get these ideas? Of course energy conservation laws consider (and implicitly include) friction losses, compression and turbulence. Now just because you are familiar with *one* form of the Bernouille equation does not mean that is the only form. It is possible to derive forms for any set of integral boundary conditions with the proviso that you follow a streamline for continuity. Finally, although you seem to have missed it, the Bernoulli equation expressly considers compression of a fluid. -it comes into the density term(s). As I said, we understand how a sail works but you seem to be struggling. Cheers MC Leonard Eulers so called "Bernoulli equation" is the 1D (one dimensional case) of his 3D equations for an non existing, mathematical modeled fluid! Hahahahhah. Does energy exist? Bernoulli equation is the integralform of Newton second law F=m*a! Bzzzzzzzzt wrong. It is easier to show the direction of the Lifting Force using Newton´s second law directly. Many books explain Lift with the so called "Bernoulli effect", which means that " high airflow velocity causes low airpressure"! Bernoulli does not say that. It is the misinterpretaion of the equation by mathematically impaired people that says that. Professor Dooley shows here below that this is wrong: According to Professor Dooley, Millerville University, it will take one generation to understand Bernoulli equation and that " high velocity does not causes low pressure". Yawn. So he's the only genius that can understand the derivation of an equation? Is this not a wonderful exaple of a one eyed man in a velley of the blind? http://muweb.millersv.edu/~jdooley/m...erap/eulap.htm Professor Dooyley writes down the page: "One confusing detail about Bernoulli's equation needs discussion: In elementary treatments it is often stated that, because of Bernoulli's equation, high velocity causes low pressure. Note the ELEMENYTARY! In this NG we are not at ELEMENTARY level and are so far above average understanding of how a sail works and how to make it work at close to 100% efficiency that people like Dooyley have nothing of value to offer. In real aerodynamic books one never finds the expression "Bernoulli Effect"! Yawn. Of course. Wings of all new airliners are almost flat on upper surface! That´s called "Supercritical Wings" and they save their operators (as example airbus340 ) some 15 % over older aircrafts (Boeing 747-400)! Now you are being really silly, do you think sailboats work in the spercritical regime? http://aerodyn.org/HighSpeed/supercritical.html They now have longer airflow path below the wing compared to to upper surface! Some Professors explains Lift with "The Circulation Theory"! But Potential Theory and it´s correction, the superpositioned "Circulation Field" is not reality, only a mathematical model! Say my model of you is a mathematical midget. Does that mean it's incorrect -just because it is a model? Cheers MC |
how a sail works, who can help me explain?
The_navigatorŠ wrote in message ...
Jan-Olov Newborg wrote: The_navigatorŠ wrote in message ... Where do you get these ideas? Of course energy conservation laws consider (and implicitly include) friction losses, compression and turbulence. Now just because you are familiar with *one* form of the Bernouille equation does not mean that is the only form. It is possible to derive forms for any set of integral boundary conditions with the proviso that you follow a streamline for continuity. Finally, although you seem to have missed it, the Bernoulli equation expressly considers compression of a fluid. -it comes into the density term(s). As I said, we understand how a sail works but you seem to be struggling. Cheers MC Leonard Eulers so called "Bernoulli equation" is the 1D (one dimensional case) of his 3D equations for an non existing, mathematical modeled fluid! Hahahahhah. Does energy exist? Bernoulli equation is the integralform of Newton second law F=m*a! Bzzzzzzzzt wrong. It is easier to show the direction of the Lifting Force using Newton´s second law directly. Many books explain Lift with the so called "Bernoulli effect", which means that " high airflow velocity causes low airpressure"! Bernoulli does not say that. It is the misinterpretaion of the equation by mathematically impaired people that says that. Professor Dooley shows here below that this is wrong: According to Professor Dooley, Millerville University, it will take one generation to understand Bernoulli equation and that " high velocity does not causes low pressure". Yawn. So he's the only genius that can understand the derivation of an equation? Is this not a wonderful exaple of a one eyed man in a velley of the blind? http://muweb.millersv.edu/~jdooley/m...erap/eulap.htm Professor Dooyley writes down the page: "One confusing detail about Bernoulli's equation needs discussion: In elementary treatments it is often stated that, because of Bernoulli's equation, high velocity causes low pressure. Note the ELEMENYTARY! In this NG we are not at ELEMENTARY level and are so far above average understanding of how a sail works and how to make it work at close to 100% efficiency that people like Dooyley have nothing of value to offer. In real aerodynamic books one never finds the expression "Bernoulli Effect"! Yawn. Of course. Wings of all new airliners are almost flat on upper surface! That´s called "Supercritical Wings" and they save their operators (as example airbus340 ) some 15 % over older aircrafts (Boeing 747-400)! Now you are being really silly, do you think sailboats work in the spercritical regime? http://aerodyn.org/HighSpeed/supercritical.html They now have longer airflow path below the wing compared to to upper surface! Some Professors explains Lift with "The Circulation Theory"! But Potential Theory and it´s correction, the superpositioned "Circulation Field" is not reality, only a mathematical model! Say my model of you is a mathematical midget. Does that mean it's incorrect -just because it is a model? Cheers MC You don´t seems to understand the fluid flow physics and it´s connections to mathematical idealized models! PIM s webpage shows the real physics! Once Professor Hoerner wrote: "Only a mathematician can create Lift by means of a Line"! (Lifting Line Theory). If you are a mathematical midget or not I don´t know! Jan-Olov Newborg |
how a sail works, who can help me explain?
Jan-Olov Newborg wrote: The_navigatorŠ wrote in message ... Jan-Olov Newborg wrote: The_navigatorŠ wrote in message ... Where do you get these ideas? Of course energy conservation laws consider (and implicitly include) friction losses, compression and turbulence. Now just because you are familiar with *one* form of the Bernouille equation does not mean that is the only form. It is possible to derive forms for any set of integral boundary conditions with the proviso that you follow a streamline for continuity. Finally, although you seem to have missed it, the Bernoulli equation expressly considers compression of a fluid. -it comes into the density term(s). As I said, we understand how a sail works but you seem to be struggling. Cheers MC Leonard Eulers so called "Bernoulli equation" is the 1D (one dimensional case) of his 3D equations for an non existing, mathematical modeled fluid! Hahahahhah. Does energy exist? Bernoulli equation is the integralform of Newton second law F=m*a! Bzzzzzzzzt wrong. It is easier to show the direction of the Lifting Force using Newton´s second law directly. Many books explain Lift with the so called "Bernoulli effect", which means that " high airflow velocity causes low airpressure"! Bernoulli does not say that. It is the misinterpretaion of the equation by mathematically impaired people that says that. Professor Dooley shows here below that this is wrong: According to Professor Dooley, Millerville University, it will take one generation to understand Bernoulli equation and that " high velocity does not causes low pressure". Yawn. So he's the only genius that can understand the derivation of an equation? Is this not a wonderful exaple of a one eyed man in a velley of the blind? http://muweb.millersv.edu/~jdooley/m...erap/eulap.htm Professor Dooyley writes down the page: "One confusing detail about Bernoulli's equation needs discussion: In elementary treatments it is often stated that, because of Bernoulli's equation, high velocity causes low pressure. Note the ELEMENYTARY! In this NG we are not at ELEMENTARY level and are so far above average understanding of how a sail works and how to make it work at close to 100% efficiency that people like Dooyley have nothing of value to offer. In real aerodynamic books one never finds the expression "Bernoulli Effect"! Yawn. Of course. Wings of all new airliners are almost flat on upper surface! That´s called "Supercritical Wings" and they save their operators (as example airbus340 ) some 15 % over older aircrafts (Boeing 747-400)! Now you are being really silly, do you think sailboats work in the spercritical regime? http://aerodyn.org/HighSpeed/supercritical.html They now have longer airflow path below the wing compared to to upper surface! Some Professors explains Lift with "The Circulation Theory"! But Potential Theory and it´s correction, the superpositioned "Circulation Field" is not reality, only a mathematical model! Say my model of you is a mathematical midget. Does that mean it's incorrect -just because it is a model? Cheers MC You don´t seems to understand the fluid flow physics and it´s connections to mathematical idealized models! Silly boy, all phsyics is model based! PIM s webpage shows the real physics! Yawn Once Professor Hoerner wrote: "Only a mathematician can create Lift by means of a Line"! (Lifting Line Theory). Hyperbole. If you are a mathematical midget or not I don´t know! At last a correct statement! Yes you don't know -in fact you have no idea! Cheers MC |
how a sail works, who can help me explain?
I'm the one who says it will obey energy conservation! What's this
"Bernouille law"? Did you just make it up? Cheers MC PS How you *think* the molecules of air 'know' there's a windsock in front of them? Jan-Olov Newborg wrote: The_navigatorŠ wrote in message I would like to see you explain why the Jetblast behind a F16 Fighting Falcon and also the Windsock seen at every airport, does not obey the "Bernoulli law" and your mathematical model! |
how a sail works, who can help me explain?
Jan,
You sure are choosing the wrong examples to biscredit Bernoulli The Name of the engine you are discribing should explain the action. F15 JET. Jet being the key word. Don't yor know how a jet operates? We have many in this group who can explain this better than I Jan again you are proving Bernoulli Theorem. A Jet is based pretty much on a venture or a Jet nozzil. The rotating blades pull air into a narrowd section or Jet, increasing the vel |
how a sail works, who can help me explain?
Sorry Jan, hit the wrong key,
But to continue the turbine fans increase the air flow thru a narrow section, there by reducing pressure( Bernoulli) The back draft you are refering to is the recovery area of the air thru the Jet. I'm not sure but this maybe the reaction area if it is so Newton's Law. I'm in over my head here but the jet is creating lower pressure by increasing velocity |
how a sail works, who can help me explain?
Jan,
I'm sorry to tell you pitotube isn't a good example of Bernoulli. A pitotube is a comparision of Impact Pressure/static pressure. It isn't a reduction in pressure due to velocity Ole Thom |
how a sail works, who can help me explain?
On Mon, 21 Jul 2003 10:16:26 +1200, The_navigatorŠ wrote:
Think about this, F=ma cannot be correct unless the object applying/experiencing F also changes energy content! Now do you get it? How's a ten pound rock sitting on the ground changing energy content? S/V Cat's Meow http://www.catsmeow.org |
how a sail works, who can help me explain?
How did it get there?
Cheers MC Gerard Weatherby wrote: On Mon, 21 Jul 2003 10:16:26 +1200, The_navigatorŠ wrote: Think about this, F=ma cannot be correct unless the object applying/experiencing F also changes energy content! Now do you get it? How's a ten pound rock sitting on the ground changing energy content? S/V Cat's Meow http://www.catsmeow.org |
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