magnetic propulsion system.

R

reactor1967

Quantum Scribe
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************************ Electromagnet
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(((((*%%%%%%%*))))))))))
(((((*%%%%%%%*))))))))))
((((((*%%%%%*))))))))))) Non-magnetic spring. Is not affected by the magnet
(((((((*%%%*))))))))))))
((((((((*%%*))))))))))))
(((##########)))))))) metal can be pulled by magnet
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((((((((((^)))))))))))))
((((((((((|))))))))))))) Momentum toward the electromagnet when powered up.

This is a electromagnet with a spring attached at the bottom that is made of a material which
is not affected by the magnetism. At the bottom of the spring is a piece of metal which is
affected by the magnetism. In theory the electromagnet should pull the piece of metal toward it causing the spring to push up against the magnetic without a opposing force thus creating momentum in the upwards direction which can be designed to be used as a propulsion system.

Can anyone find a flaw with this?

The ( and % are spaces. Its very hard to post anything here unless it is a link to something.
Its a diagram showing my concept. [image]http://intlcommercetradingcorp.com/reactor1967/emp.jpg[/image]
 
Can anyone find a flaw with this?
Click to expand...

Several. Most of the problems likely stem from assumptions you have made that you have not stated. So let me question you about some things, to see if you would be willing to state what you thought going into your analysis.

1) Are you assuming that the momentum is due to the mass of the piece of metal times its velocity towards the magnet?
2) If so, did you assume this momentum remains constant from the time you turn on the magnet?
3) Are you aware that a spring is an energy storage device? Do you know what a "spring constant" tells us about a spring's ability to store energy?
4) If so, what happens to that stored energy when you turn off the magnet?
5) What is the magnet attached to (if anything)? ( a truss that is connected to the ground?)
6) If not affixed to a truss that is attached to the ground, what would stop the magnet from moving upwards as the spring gets compressed?
7) What sort of electrical signal is driving the eletcromagnet? DC or AC?
8) Can you draw a proper free-body diagram of all the forces involved (including the transient ones) and use F=ma along with several other equations of physics to program a simulation to tell you what should happen?
9) Do you know that it is not momentum that creates a propulsive force, but rather the rate of change of momentum that results in such a force? (This is how jet engines create thrust).
10) Can you understand that while the initial rate of change of momentum will be positive (the metal accelerates towards the magnet) that eventually the rate of change of momentum of the metal will become negative?

RMT
 
The ( and % are spaces. Its very hard to post anything here unless it is a link to something.
Its a diagram showing my concept.
Click to expand...

I can definitely help you with this. Do you have a drawing program of any sort? (The answer to this is "yes" if you have any Windows OS, since MS Paint is a drawing program) You can draw anything in a program like this (or a more engineering-oriented program like MS Visio, or AutoCAD, or even MS Powerpoint) and then save the image as a .GIF or .JPG file. Once you have such a file, you can create a (free) account at a website like "imageshack.com" or "photobucket.com" where you can upload the .GIF or .JPG file and include the URL for that image inside the "IMG" tags in your posts. Here is an example of what the code looks like, just replacing the normal HTML brackets ("[") with curly brackets ("{"):

{IMG}http://i124.photobucket.com/albums/p32/RainmanTime/Sysmodel.gif{/IMG}

Embedding this code in this post but with the proper brackets results in the image stored at photobucket.com to be displayed here. Like this:

Sysmodel.gif


Hope that helps...
RMT
 
The electromagnet & piece of metal will experience an equal & opposite force. The system will contract/expand, but there will be no net linear force.
 
good to see you back ruthless:

what if the magnets were angled though?
Click to expand...

How do you mean? Could you draw and post a diagram?

would it have linear force then?
Click to expand...

It is not that there are no linear forces in reactor's setup. In fact, an electromagnet actually creates a magnetic attractive force between itself and the metal plate when it is first turned on. However, for many reasons (one being the physical nature of a spring to store energy) the forces do not remain constant in magnitude or direction. This is, in point of fact, one of the things that makes engineering "hard". Being able to recognize what is a "statics problem" (where all forces remain constant and nothing is moving relative to some fixed reference) which is a fairly easy problem to solve, and what are the more difficult-to-solve "dynamics problem". Whether a statics or dynamics problem, solving either type of problem relies most heavily on drawing a proper free body diagram, and labeling ALL the forces that currently act and/or will act on the bodies involved.

This is the first and most important lesson that engineers are taught in how to solve static and dynamic physical problems: Step 1 - Draw a Free Body Diagram!

RMT
 
"good to see you back ruthless:"

thanks, good to be back. been pretty bored without tti lol.


"How do you mean? Could you draw and post a diagram?"

no i cant, but i can try my best to explain it. when two magnets are perfectly flat and placed on top of each other and they are facing positive positive, or negative negative, they push away. if you slightly angle one, it will move in the direction it is angled. so if you were to make a magnetic road and then put magnets on the bottom of a car with some kind of device that angled the magnets on the bottom of the car in different directions, would it be able to be driven similar to a car?

i'll try to dust off the 'ol scanner tomorrow and see if i can whip something up.
 
ive actually been thinking about this idea since i was very young. i even built a few models when i was younger. my idea was a little different though. i wanted to use earth magnets like neodymium or strontium. it would be clean, free energy. would that rock or what?
 
Several. Most of the problems likely stem from assumptions you have made that you have not stated. So let me question you about some things, to see if you would be willing to state what you thought going into your analysis.

1) Are you assuming that the momentum is due to the mass of the piece of metal times its velocity towards the magnet?
2) If so, did you assume this momentum remains constant from the time you turn on the magnet?
3) Are you aware that a spring is an energy storage device? Do you know what a "spring constant" tells us about a spring's ability to store energy?
4) If so, what happens to that stored energy when you turn off the magnet?
5) What is the magnet attached to (if anything)? ( a truss that is connected to the ground?)
6) If not affixed to a truss that is attached to the ground, what would stop the magnet from moving upwards as the spring gets compressed?
7) What sort of electrical signal is driving the eletcromagnet? DC or AC?
8) Can you draw a proper free-body diagram of all the forces involved (including the transient ones) and use F=ma along with several other equations of physics to program a simulation to tell you what should happen?
9) Do you know that it is not momentum that creates a propulsive force, but rather the rate of change of momentum that results in such a force? (This is how jet engines create thrust).
10) Can you understand that while the initial rate of change of momentum will be positive (the metal accelerates towards the magnet) that eventually the rate of change of momentum of the metal will become negative?

RMT

Recursion. Closed-loops. Orobouros.
Click to expand...

RMT:

You have clearly showed that there is a lot I have not considered.

1. On momentum I was meaning the energy that the spring stored after it overcame the weight of the electromagnet and was released into forward movement of the of electromagnet, spring, and metal together.
2. I did not assume the momentum would remain constant because I new things would change with this setup as the metal and spring moved.
3. Yes I was aware about a spring as a energy storage device. But I did not know what a "spring constant" tells me about a springs ability to store energy? I am not familiar with that.
4. When I turn off the magnet the energy in the spring could be released in the other direction but I was wondering if the magnetic could release that energy slowly enough not to affect all of the forward momentum. Forward momentum - backwards momentum if the forward was greater than the backward momentum then the forward momentum would not cancel out completely. But, on the flip side as the electro-magnet moved depending on the magnetic field the springs energy could also be released. What do you think about this setup leaving enough energy so that the electro-magnet still moves forward?
5. The electro-magnetic would not be attached to anything except the spring but the metal would be attached to the spring somehow and the spring would be attached to the electro-magnet.
6. What would stop the magnetic from moving as the spring compressed? I hope nothing would stop it that was my point. I wanted to make the electro-magnet move and keep moving.
7. The electrical signal would be DC. But, now that I think about it AC might work too because the metal would still be attracted by either pole. AC at some frequency might be better. Well problem is the spring would have to release at less energy than it released when it was compressed. What do you think about this?
8. On drawing the forces I would need to work with that. I am not use to drawing forces and I probably have a lot to learn in that area. If I was going to pursue this further drawing the forces would probably be the next thing I would want to do or learn how to do.
9. No, I did not know that it was the rate of change that creates force. I always thought of it as a constant. I guess I was wrong.
10. Yes I can understand the rate of change of the metal will be negative. I did not understand this before I read your post.

Thank you. Reactor
 
Thank you. I did not know about those web sights I will take a look at them and start doing that. While we are on the subject I have a question. When I post I see this at the bottom "You may attach a file while editing. How does that work?
 
Reactor,

Glad you got the hang of the drawing and image posting here so quickly. I am also glad that you are rapidly seeing the engineering issues with your idea. I am not trying to insult you, only get you to consider things that will move you along in understanding.

5. The electro-magnetic would not be attached to anything except the spring but the metal would be attached to the spring somehow and the spring would be attached to the electro-magnet.
Click to expand...

I could go thru all your answers, but as I say above these were meant to get you thinking about things you may have (implicity or explicity) assumed at the outset of your idea. This answer cuts to the chase, which is what I wish to do. So let me assume the magnet sits in a "cradle" of sorts which holds it above the ground, but to which it is not attached/affixed in any way. Now imagine that I can actively control the speed at which the metal plate approaches the magnet and compresses the spring. (In reality I could certainly do this by controlling the expansion and contraction of the magnetic field, but that is more advanced than I need you to think right now)

Imagine I have two distinct speeds that I can command the metal plate to approach the magnet when it is turned on: REALLY slow and REALLY fast. In the REALLY slow case the spring is just going to compress and the magnet will not move at all (if it is heavy enough). There will be a point of equilibrium where the tension in the spring balances the maximum magnetic forces emitted by the magnet. So you would see the metal plate move up a bit and then stop. In the REALLY fast case the acceleration of the plate against the spring would "pop" the magnet in the upwards direction for a moment and then the magnet would fall into a rest state similar to the really slow case (unless the acceleration was so great it popped the magnet out of its cradle). This imagination process helps demonstrate why it is the TIME RATE OF CHANGE OF MOMENTUM (in calculus this is symbolically expressed as d(mV)/dt) that impacts the motion of an object. Quite literally, this is proof that Newton's Second Law is correct.

But now let me REALLY cut to the chase and save you having to think about problems that other people already thought out, made mistakes, and have progressed beyond. I can fully see the idea behind what you are trying to do with this setup, and you may not even realize this is where you are going with it (expressed in these words): You are trying to extract energy from the universe by actively coupling with all the rest of the matter in the universe. If you don't understand that, it is OK... but you might need to trust me that this is the bottom line of what your idea is trying to do. It is called the Mach Effect.

Now let me point you to a guy who is not only an engineer but also teaches physics at Cal State University, Fullerton... which is right down the highway from where I teach at Cal Poly, Pomona. His name is Dr. James Woodward and he has been working on experimental versions of what he calls the Mach-Lorentz Thruster (MLT). (NOTE to the wiki that follows: Dr. Woodward does NOT like calling it the Woodward Effect. He attributes all the knowledge behind it to Mach's Principle as aided by Lorentz).

http://en.wikipedia.org/wiki/Woodward_effect

The Mach Effect is strongly linked to Mach's principle, the concept that all momentum is linked to the mass of the rest of the universe, as well as the general theory of relativity.
Click to expand...

I am pointing you to his work because you can save a lot of time (not having to reinvent the wheel, not having to make the same mistakes he made, leverage his explanation of the effect, etc.) by following his work. If there is any merit to the idea, he and his team will be the first to quantify it because he is doing things in a REAL lab and he has derived real equations that predict the effect he is trying to test for. So far, the results have been disappointing and nothing has shown any previous knowledge of physics to be grossly in error.

I also offer this because, if you read up on what he is doing, you will likely learn a lot more about engineering analysis and how what may seem obvious to you may have problems that you never considered.

RMT
 
While we are on the subject I have a question. When I post I see this at the bottom "You may attach a file while editing. How does that work?
Click to expand...

I do not know, because when I am writing a reply I do not see any such message as this. If you can help me find exactly where it says this I might be able to help. But as for now..sorry!

RMT
 
Deleted naughty boy tirade.
Click to expand...

I don't mean to be insulting, but that is not a DC signal. Assuming the y-axis is voltage, then as the voltage changes, so does the current, and that would make this an AC signal. Technically, this would be a shaped sawtooth AC signal with the shaping on the downside of each sawtooth caused by an R-L effect (most likely, but I am not positive).

RMT
 
That is actually what the signal looks like RMT.

The line is actually 0 voltage. the ramp up is actually the inductive resistance and the drop signal would be the power side.

All he is showing is that he is turning it on and off at a set voltage and a certain frequency.

For it to be an AC signal the voltage would actually have to phase to below the line.
 
That is actually what the signal looks like RMT.

The line is actually 0 voltage. the ramp up is actually the inductive resistance and the drop signal would be the power side.

All he is showing is that he is turning it on and off at a set voltage and a certain frequency.
Click to expand...

So then it is neither AC nor DC (strictly speaking), but rather more what we call Pulse Width Modulation (PWM) with a long decay time constant.

For it to be an AC signal the voltage would actually have to phase to below the line.
Click to expand...

Not always. DC bias could still make for an alternating waveform without any zero crossings. Yes?

Sorry, I just love technical nitpicks...keeps one sharp! :D
RMT
 
no i cant, but i can try my best to explain it. when two magnets are perfectly flat and placed on top of each other and they are facing positive positive, or negative negative, they push away. if you slightly angle one, it will move in the direction it is angled. so if you were to make a magnetic road and then put magnets on the bottom of a car with some kind of device that angled the magnets on the bottom of the car in different directions, would it be able to be driven similar to a car?
Click to expand...

Well, you should be happy to know that, in a crude way, this is kind of the basis for MagLev trains! Although they do not have to angle the magnets to get forward motion. This is all handled by the flow of current through the magnets. The rate of change of current is directly proportional to the velocity induced between the two charged objects (the electromagnet and the tracks).

Not too practical for roads; however, because we would have to change the entire road surface infrastructure to support it. /ttiforum/images/graemlins/smile.gif
RMT
 
"Not too practical for roads; however, because we would have to change the entire road surface infrastructure to support it."

we repave roads every few years anyways, so why not? repave a road every few years? or pave it once and never look back? sounds purdy practical to me. now i will admit its not the super moneymaker that corporations want, but it would make quite a few people happy.

to me, it would be worth throwing away every car ever made, and i love cars. theres just too many positives and no negatives.

i know this will exist one day, but i wonder if i will still be alive to see it.
 
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