Some Secrets of Fans

[Swisaw]

Some Secrets of the fans


A fan creates an air stream when it is operating. This air stream is made up of lower pressure at the front and higher pressure at the back. This air stream is the output of the fan. In other words, the output of the fan made up of lower pressure output at the front and higher pressure output at the back.


Highest natural air, atmospheric, pressure is 14.7 psi or 1.00kg/sq centimetre. So theoretically lower pressure output can not become less than -14.7 psi or -1.00kg/sq centimetre but higher pressure output always is more than 14.7 psi or 1.00kg/sq centimetre. We can put this in a formula. If the fan can generate a pressure of 0.25kg/sq centimetre the output at the front will become – 0.25kg/sq cm and the output at the back will become 1.00kg/sq cm + 0.25kg/sq cm


Theoretically a fan can be made to generate a pressure higher than 1.00kg/sq cm or 14.7 psi but this fan can not generate an output at the front lower than -1.00kg/sq cm or -14.7 psi. This is because air weight or atmospheric pressure at the front of the fan, when it is not operating, is 1.00kg/sq cm or 14.7 psi. So it is impossible for the fan to create a lower pressure output less than -1.00kg/sq cm or -14.7 psi


A fan operates with an external input. An electric fan operates with an external electric input. Not all the external input converted to the thrust of the fan to generate both outputs at the front and at the back. Only the mechanical efficiency, input efficiency, of the fan converted to a thrust to generate both outputs. Some external inputs wasted as heat because of the friction of the fan. The rest of the input is the efficiency of the fan and converted to a thrust. Lets call the efficiency of the fan as 'input efficiency'.


So how this input efficiency used to operate the fan? It is used to spin the fan and when the fan spins it creates an air stream, which is made up of lower pressure output at the front and higher pressure output at the back. But how does the fan generate this air stream? The fan throws out or pumps out air between its blades backward, which creates high pressure output air stream at the back. In other words, all input efficiency used as a thrust by the fan to spin to pump out or throw out air between its blades backward.


But the question is this: if all input efficiency goes to generate a thrust to spin the fan to pump out air between its blades backward to generate the air stream at the back, how is the front air stream generated? The answer is easy; when the fan pumps out air between its blades, it creates lower atmospheric pressure between blades. This lower atmospheric pressure between blades is lower than the external natural atmospheric pressure. So natural atmospheric pressure at the front and at the back tries to enter between blades to bring back atmospheric equilibrium between blades.


However the fan creates a pressure at the back higher than the atmospheric pressure. So the atmospheric pressure at the back can not do any thing. But the fan doesn't do any pressure changes at the front. So the atmospheric pressure at the front rushes into the space between blades to bring back atmospheric pressure equilibrium. This act causes the air stream output at the front

 

[vvaannmmaann]

Yeah and ?

 

Fantastic......

 

[Swisaw]

If the fan can generate a pressure of 0.25kg/sq centimetre the output at the front will become – 0.25kg/sq cm and the output at the back will become 1.00kg/sq cm + 0.25kg/sq cm

Incorrect. this is the correct version:


If the fan can generate a pressure of 0.25kg/sq centimetre the output at the front will become – 0.25kg/sq cm and the output at the back will become 0.50kg/sq cm. This is twice the output at the front. It becomes so because half of the back output is atmospheric pressure differentiation between the front and back. The fan generates an output of -0.25kg/sq cm at the front. So atmospheric pressure at the front becomes 1.00kg/sq cm - 0.25kg/sq cm = 0.75kg/sq cm . But atmospheric pressure at the back remains at 1.00kg/sq cm and 0.25kg/sq cm higher pressure of the fan added to it. So the total pressure at the back of the fan becomes 1.25kg/sq cm. This is higher than the pressure at the front by 0.50kg/sq cm.

 

[Swisaw]

Fantastic......

Many thanks Sir Earl.

 

[Swisaw]

Yeah and ?

You are right.

In conclusion, theoretically, a fan generates an output higher than the input by three times provided the fan doesn't generate a pressure higher than atmosheric pressure. Only the output at the back, which takes all the input, usually put into use. The output at the front, which doesn't have any cost, has not been put into use in any application. If this output put into use the cost of operating a fan will be reduced by as much as half. This is the purpose of my HAAM concept at this link:

http://haam.thrilling.me.uk/

 

[MikeJ]

In conclusion, theoretically, a fan generates an output higher than the input by three times

The greatest minds in on the planet have always said you can't get more out of a machine than you put in. Newton, Einstein, etc, all understand that idea.

However, a van driver that patented gravity thinks otherwise.

 

[Swisaw]

The greatest minds in on the planet have always said you can't get more out of a machine than you put in. Newton, Einstein, etc, all understand that idea.

However, a van driver that patented gravity thinks otherwise.

My dear Coyoti,

When and where did I say you can get out more than what you put in a machine? obviously you have not understood the concept. Let me to explain it in a culturally compatible to the frame of your mind.

If you kick a ball very high the ball will come down after your input, the energy of your kick, becomes zero. After that you have nothing to do with the ball. Gravity takes control of the ball and brings it down.


The same thing happens within the region of low pressure infront of the fan. This low pressure is a hole in the air, caused, but not created, by the fan or it doesn't cost external input of the fan. All external input goes to spin the fan. When the fan spins it pumps out air between its blades to the back. This creates a vacuum between blades. The pressure of this vacuum is lower than external pressure. So external pressure rushes to to fill the vacuum. But as long as the fan spins, it can not fill this vaccuum, which causes lower pressure at the front. As you see this lower pressure has nothing to do with the input to the fan. It is driven by the weight, potential energy of air, and this weight or potential energy of air is generated by gravity. In other words the input of the lower pressure comes from the gravity, not from the input of the fan. This doesn't mean you got out more than you put in.

It is similar if you are standing 10 metres away from the top of a 100 metre high cliff. You throw a ball of 0.25kg to the tip of the cliff. After that the ball falls to the bottom of the cliff. You added 0.25kg x 10 gravity x 10 metre = 25J energy to the ball. But when the ball falls to the bottom it has generated 0.25kg x 10 gravity x 100 metre = 250.00J energy. This is more than the energy you used by 250 - 25 = 225J energy.

You see for an input cost of 25J you generated 250J. But your input used only across 10metres. After that you didn't add any more input. It is the same thing with low pressure except it doesn't generate an amout of energy more than the input to the fan.
That is how the low pressure side of the fan generates an output with a costless input.

 

[MikeJ]

Ok, stop it now.

 

[affshow]

MikeJ, you did a great job.

 

[Swisaw]

Ok, stop it now.

I don't think you and your supporters have a clue about physics of fan and falling ball.

 

[MikeJ]

I'm trying not to swear at you. Honestly, I am.

I'll type this slowly, in the hope that you can understand.

The ball falls because it loses potential energy. It has potential energy because it's starting place is higher than its final resting place. It has less energy after you've kicked it, because it's at a lower place than its starting place.

That's why it moves further than theoretically possible from the force a person exerts on it. I fully understand the concept of gravity. It involves a two bodies being pulled towards each other, due to their mass.

Gravity has nothing what so ever to do with how a fan works. A fan works by displacing the air in the spaces between the blades. The blades push the air out, causing a slight vacuum which pulls more air in.

Putting energy into the fan generates air movement. The air movement is less than the energy you put into the fan. The rest goes to heat and a bit of noise.

 

[MikeJ]

The same thing happens within the region of low pressure infront of the fan. This low pressure is a hole in the air, caused, but not created, by the fan or it doesn't cost external input of the fan. All external input goes to spin the fan. When the fan spins it pumps out air between its blades to the back. This creates a vacuum between blades. The pressure of this vacuum is lower than external pressure. So external pressure rushes to to fill the vacuum. But as long as the fan spins, it can not fill this vaccuum, which causes lower pressure at the front. As you see this lower pressure has nothing to do with the input to the fan. It is driven by the weight, potential energy of air, and this weight or potential energy of air is generated by gravity.

This is just wrong. Of course the low pressure at the front of the fan is caused by the fan spinning. If the fan didn't spin, then there would be no low pressure. If the fan stops, the pressures would be equal. If the fan spins, it pushes the air out, sucking air in at the front.

 

[Swisaw]

I'm trying not to swear at you. Honestly, I am.

I'll type this slowly, in the hope that you can understand.

The ball falls because it loses potential energy. It has potential energy because it's starting place is higher than its final resting place. It has less energy after you've kicked it, because it's at a lower place than its starting place.

That's why it moves further than theoretically possible from the force a person exerts on it. I fully understand the concept of gravity. It involves a two bodies being pulled towards each other, due to their mass.

Gravity has nothing what so ever to do with how a fan works. A fan works by displacing the air in the spaces between the blades. The blades push the air out, causing a slight vacuum which pulls more air in.

Putting energy into the fan generates air movement. The air movement is less than the energy you put into the fan. The rest goes to heat and a bit of noise.

Well, it seems we are speaking the same language but there is some misunderstanding between us because of the established norms and traditions. You are conditioned with existing established norms and traditions, which is not easy for you and the majority to break. But I have broken this established norms and traditions very long ago. Because of that I can understand natural physics better some times like the case of the fan.

For example when you drink your milkshake with the straw, you think you are sucking it. But I say: 'NO', you are not sucking it. the concept of sucking practically doesn't exist. You create a vaccuum inside the straw. The pressure inside the straw becomes less than external pressure. So the higher external pressure pushes the milkshake across the straw to your mouth. You only put an input to create a vacuum inside the straw. But you didn't put any input to the external higher pressure to push the milkshake to your mouth. It is an output without input cost. it happened because of the pull og gravity on the air.

The same things happen with fans. when a vacuum created between fan blades, higher atmospheric pressure pushes air between blades from the front, the fan doesn't draw the air to itself. So the concept of drawing air by the fan doesn't exist practically, it is an established plousible norms and traditions. The air goes to the fan because of the lower pressure between the blades of the fan, the fan doesn't draw the air. The act of air going to the fan doesn't take any input used to operate the fan. This act of air going to the fan has an input, which is gravity, doesn't have input cost, if exploited increases fan efficiency without extra cost.

Now does this ring a bell?

 

[MikeJ]

For example when you drink your milkshake with the straw, you think you are sucking it. But I say: 'NO', you are not sucking it. the concept of sucking practically doesn't exist. You create a vaccuum inside the straw.

You create that vacuum by sucking!

 

[MikeJ]

The same things happen with fans. when a vacuum created between fan blades, higher atmospheric pressure pushes air between blades from the front, the fan doesn't draw the air to itself.

Yes it does. The fan creates the low pressure between the blades.

So the concept of drawing air by the fan doesn't exist practically, it is an established plousible norms and traditions. The air goes to the fan because of the lower pressure between the blades of the fan, the fan doesn't draw the air.

Yes it does. The fan creates the low pressure between the blades.

The act of air going to the fan doesn't take any input used to operate the fan.

Yes it does. The fan creates the low pressure between the blades.

This act of air going to the fan has an input, which is gravity, doesn't have input cost, if exploited increases fan efficiency without extra cost.

It isn't gravity! It's the difference in pressure.

 

[Davek0974]

.

Cant find out to delete message:|

 

[Swisaw]

Yes it does. The fan creates the low pressure between the blades.



Yes it does. The fan creates the low pressure between the blades.



Yes it does. The fan creates the low pressure between the blades.



It isn't gravity! It's the difference in pressure.

Yes, it is, it is a gravity.

But first let this removal man to give you another surprise. The term 'Atmospheric Pressure' is wrong. Because atmosphere is an open system and an open system can not have a pressure. But amtosphere has a weight. Therefore the correct term is 'armospheric weight'.

But what is the difference between atmospheric pressure and weight? Atmospheric Weight is the pull of gravity between earth and the volume of air on earth.

Atmospheric pressure is applicable for example in tyres, in which the air has pressure against all internal surface of the tyre and a tyre is a closed system but not the atmosphere, which is an open system.

Lets go back to our subject, the secret of fans. Please make the following experiment:

Put your hand in an empty water container. Now fill the container with water untill your hand covered. Now take out your hand inside water. You will notice as soon as you took out your hand, water flowed into the space your hand left. Now you only put an input to generate one output, which is to take oput your hand inside water. But you also caused another output, which is the flow of water to fill the space your hand left behind. You didn't put any input into the flow of the water.

The same thing happens with fans. The flow of air to the fan doesn't take input from the fan. It happens because of the weight of the air, which is heavier outside than the weight of the air between the blades.

 

[Scott-Copywriter]

It is similar if you are standing 10 metres away from the top of a 100 metre high cliff. You throw a ball of 0.25kg to the tip of the cliff. After that the ball falls to the bottom of the cliff. You added 0.25kg x 10 gravity x 10 metre = 25J energy to the ball. But when the ball falls to the bottom it has generated 0.25kg x 10 gravity x 100 metre = 250.00J energy. This is more than the energy you used by 250 - 25 = 225J energy.

You see for an input cost of 25J you generated 250J. But your input used only across 10metres. After that you didn't add any more input. It is the same thing with low pressure except it doesn't generate an amout of energy more than the input to the fan.

But to get yourself up to the height of 90 metres (10 metres below the 100 metre cliff edge) to throw the ball up, you've used energy by working against gravity to get yourself up there.

That's where the missing input energy is. To generate 250J, you will take the 25J of input from throwing the ball 10 metres up to the 100 metre mark, plus the input of getting yourself up to the 90 metre mark to throw the ball.

Gravity is a form of potential energy only. You can take out only what you put in. What you're trying to do here break the laws of thermodynamics.

 

[internetspaceships]

Wasn't Swisaw trying to make a self levitating contraption too a few years ago?

 

[MikeJ]

I don't need to do the hand in water trick.

If I filled a bucket with water, and put my hand in, the level would rise. Trust me on this, Archmides knew a few years back so I think we can assume this is right. Me putting my hand in caused the water to rise. The rise in level is an increase in the potential energy of the water. Taking the hand out results in that energy being converted into dynamic energy.

All you're doing by putting your hand in initially is "storing" a bit of energy that the water would otherwise have lost.

The air on your fan can only flow into the low pressure area if the fan creates the low pressure area in the first place. It's not "extra" energy.

 

[Swisaw]

I don't need to do the hand in water trick.

If I filled a bucket with water, and put my hand in, the level would rise. Trust me on this, Archmides knew a few years back so I think we can assume this is right. Me putting my hand in caused the water to rise. The rise in level is an increase in the potential energy of the water. Taking the hand out results in that energy being converted into dynamic energy.

All you're doing by putting your hand in initially is "storing" a bit of energy that the water would otherwise have lost.

The air on your fan can only flow into the low pressure area if the fan creates the low pressure area in the first place. It's not "extra" energy.

I didn't say to put your hand in water. Go back read it again carefully to see what I am saying.

 

[Swisaw]

But to get yourself up to the height of 90 metres (10 metres below the 100 metre cliff edge) to throw the ball up, you've used energy by working against gravity to get yourself up there.

That's where the missing input energy is. To generate 250J, you will take the 25J of input from throwing the ball 10 metres up to the 100 metre mark, plus the input of getting yourself up to the 90 metre mark to throw the ball.

Gravity is a form of potential energy only. You can take out only what you put in. What you're trying to do here break the laws of thermodynamics.

I didn't say to get yourself there. I said you were there. Go back to read it again carefully to see what I am saying.

 

[MikeJ]

I didn't say to put your hand in water. Go back read it again carefully to see what I am saying.

I didn't say you did.

Go back and read what I said.

 

[Swisaw]

I didn't say you did.

Go back and read what I said.

No you did. This is what you said:

If I filled a bucket with water, and put my hand in, the level would rise. Trust me on this, Archmides knew a few years back so I think we can assume this is right. Me putting my hand in caused the water to rise. The rise in level is an increase in the potential energy of the water. Taking the hand out results in that energy being converted into dynamic energy.

As you see this has nothing to do with what I said. I said put your hand in an empty water container and then fill it with water until your hand covered. This is a lot different than puting your hand in water.

You also made another incorrect statement. You admitted when the fan spins it pushes air out between the blades. This is the same thing I stated. But you also claimed the fan pulls the air towards itself from the front. This contrdicts your previous statement. Because the fan can do only one thing, it can not do two things at the same time. It is obvious how the fan pushes out air between the blades. But tell me how the fan pulls the air from the front towards itself?

 

[MikeJ]

I also said....

All you're doing by putting your hand in initially is "storing" a bit of energy that the water would otherwise have lost.

It would be a great help if you actually read people's posts.

As for your other comment...

Look at a desk fan, stood on a table, spinning.

It pushes air out from between its blades backwards.
That creates a low pressure area between its blades, that sucks air in from the front.
It exerts a downwards force on the table. That force is uneven, due to the torque of the motor.
It emits some heat and noise energy.

It does all those things. I've no idea where you've got the idea that it can only do one thing.

If I drive my car forwards one meter, I displace the air in front of the car. The space that the car formerly ocuppied would be a vacuum, but of course the vacuum sucks the atmospheric air into that space. Ooh look! Two things! Moving the air at the front, sucking air at the back. I'm off to the patent office.

 

[simon field]

This is the stuff!

 

[MikeJ]

ocuppied

Rubbish spelling caused by me trying to type while eating breakfast at the same time.

(ooh, look at me, doing two things at the same time!)

 

[Davek0974]

Was more fun when we could discuss rel**ion

 

[Cylon]

Well I wont be looking at a fan the same way again now all the myth and mystery has been exposed. Isn't science just a form of religion that just tries to logically explain away and rationalise the true reality that everything just works by magic..

 

[Swisaw]

I also said....



It would be a great help if you actually read people's posts.

As for your other comment...

Look at a desk fan, stood on a table, spinning.

It pushes air out from between its blades backwards.
That creates a low pressure area between its blades, that sucks air in from the front.
It exerts a downwards force on the table. That force is uneven, due to the torque of the motor.
It emits some heat and noise energy.

It does all those things. I've no idea where you've got the idea that it can only do one thing.

If I drive my car forwards one meter, I displace the air in front of the car. The space that the car formerly ocuppied would be a vacuum, but of course the vacuum sucks the atmospheric air into that space. Ooh look! Two things! Moving the air at the front, sucking air at the back. I'm off to the patent office.

Let us to simplify this.
OK, we agree that when the fan spins it pushes air out between its blades backward. But we disagree how the air comes to the fan from the front to replace displaced air between blades.

You say the fan sucks or pulls the air to itself from the front. I say the air pushed to the fan, the fan doesn't suck or pull it.

I can explain my point. The air pushed to the fan from the front because the weight of external air is heavier than the weight of air between the blades of the fan. So external air weight pushes air to the space between blades to bring back air weight equilibrium.

Ok, now you explian to me how the fan sucks or pulls the air to itself? tell me exact mechanism.

 

[MikeJ]

The "weight" of the external air is heavier because the blades of the fans have pushed the previous air out.

If the fan isn't moving, then all the air in the vicinity is the same "weight". Once the fan moves, the air doesn't suddenly become heavier in front of the fan. Therefore, the movement must be due to the blades causing a reduction in the "weight" of the air in the fan blade spaces.

 

[Davek0974]

Am i the only one that cannot make any sense out of this discussion???

AFAIK, the moment it starts to rotate, a fan displaces the air immediately in front of its blades in a forward motion (for a forward blowing fan of course), this creates an area of lower pressure behind the blades, free air rushes into this lower pressure area to achieve equilibrium, this air is then pushed forwards by the next blade, rinse and repeat.

I see no mention of airfoil cross section or blade structure either.?????

 

[MikeJ]

I'm with you, Dave.

Swisaw seems to think the inrush of air is nothing to do with the blades turning.

 

[Davek0974]

Exactly, i view the blades as a set of moving inclined planes, the action of them moving through the air consumes energy and performs work i.e. they move the air.

Friction comes into play, as does blade design and blade count - 2,3,4,5 blades etc. but i can see no mention of gravity anywhere in my texts on fans, gravity has no effect as the blades are balanced. Altitude does have a small effect but only so much when the fan is connected to the front of a turbo-prop engine on a plane I don't think the altitude of my desk fan really matters on the scale of things

 

[Scott-Copywriter]

I didn't say to get yourself there. I said you were there. Go back to read it again carefully to see what I am saying.

You weren't just "there" though. This is the whole point which makes your argument completely wrong. You're claiming that the output is far higher than the input, but to come to that conclusion, you're just pretending that the energy required to get the person up to the 90m mark to throw the ball 10m up so it can fall 100m doesn't exist or isn't required.

That is the energy which balances out the equation, which you're choosing to just ignore so your argument checks out.

 

[Davek0974]

You weren't just "there" though. This is the whole point which makes your argument completely wrong. You're claiming that the output is far higher than the input, but to come to that conclusion, you're just pretending that the energy required to get the person up to the 90m mark to throw the ball 10m up so it can fall 100m doesn't exist or isn't required.

That is the energy which balances out the equation, which you're choosing to just ignore so your argument checks out.

Even if you were born on that ledge at 90m, the energy was expended by your parents surely, at some stage that energy must have been used surely?

 

[Scott-Copywriter]

Even if you were born on that ledge at 90m, the energy was expended by your parents surely, at some stage that energy must have been used surely?

That's right. You will gain more energy by allowing a ball to drop 100m after throwing it 10m up from a 90m ledge, but the energy getting you and the ball up to that 90m ledge and pushing against gravity to do so must be taken into account. Nothing and no one can just "appear" there with no energy input at any point.

 

[kulture]

Perhaps he is forgetting the initial earthquake that raised the ground up 90m.

 

[vvaannmmaann]

Maybe a Mod could pull the plug out?