Steam Powered VTOL: Exploring an Efficient Air Compression Method

[leviterande]

Hi everyone! this is my first post here and I would like to discuss a concept I have.
If you didnt hear about coanda saucers , the principle is to get as fast and high pressurized air as possible tangentially just above a curved surface, to create a low presure, suction and entrainment of air.

just a small demonstration:


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Just as the title says I wonder if it is possible to simply have a steam powered vtol. Eventhough that sounds very unreal it may not bethat way.

The idea is about building a so called a "coanda effect" flying craft.
I have seen all those toys/prototypes on the net and they are all inefficient.

The advantages over a helicopter are many, no rotors, no huge complexities etc. The huge disadvantage however is how to supply the COMPRESSED AIR EFFICIENTLY! What simply are used today on coanda prototypes are only air impeller-compressers.

The efficieny of the best air compressors to supply the required CFM at the required PSI is very low. So , from there I got the thought of why not just somehow "directly move" the air through the nozzle without "smashing and breaking" the air with the inefficient impellers!

Now I am far from experienced with steam.. but i know that there would be no moving parts and eventhough they can be heavy, they could be worth it.

Why about a steam boiler and a steam ejecter that ejects the superheated steam jet above the curved surface?
The million dollar question is and the main purpose of the thread is to see if high pressurized steam can be produced with less power and less weight than with air compressors. After all we need to produce as high pressure and air volume as possible for a given horsepower.
Best Regards
/Carl P. Malm

 

[russ_watters]

What you are suggesting is to build a ring shaped craft with a cross sectional area like that shown in the video, then blow steam horizontally across it through jets, also like in the video?

It would work, but it couldn't possibly produce as much lift as if you just pointed the jets themselves at the ground.

 

[leviterande]

What you are suggesting is to build a ring shaped craft with a cross sectional area like that shown in the video, then blow steam horizontally across it through jets, also like in the video?

It would work, but it couldn't possibly produce as much lift as if you just pointed the jets themselves at the ground.

I am wondering the same thing but the coanda effect should make the lift stronger than the component of steam-jet alone.


/Carl

 

[Borek]

I don't think so. You may call it as fancy as you want, but you are basically dealing with momentum conservation - for the aircraft to go up enough air must go down.

 

[leviterande]

I don't think so. You may call it as fancy as you want, but you are basically dealing with momentum conservation - for the aircraft to go up enough air must go down.

so I assume if we use an air compressor to develop the high pressure and suitable cfm(instead of using steam) the case would be the same i.e. as russ_watters says:

"It would work, but it couldn't possibly produce as much lift as if you just pointed the jets themselves at the ground."

The second point : would it be the same with air compressor , would the compressed air needed for coanda operation to be huge enough to lift up if it was pointed down? .. because in this case... isn't the air compressor even less efficient than steam boiler?, in developing pressurized air. And I am talking about the power input vs the aircompressed/steam output

Borek, you don't need to have the "air down" in order to lift up. all airplanes mostly use "air down" to bring them up but there are other ways to produce a partial vacuum or low pressure above a surface and you can lift up without any down wash. I am not saysing though that it is efficient.. I am looking for an EFFICIENT way of REMOVING the air on the top instead of PUSHING the air down as all the aircraft do.

all aircraft obtain their lift "mostly" from the air down but I want the lift to be obtained "mostly" from the ambient atmospheric airpressure pushing you automatically as you lower the pressure above it a good deal.. the qustion is how to efficintly do that.

 

[Vanadium 50]

When you remove the air from the top, where do you put it? If your answer is "lower", you're pushing air down. If your answer is "higher", you're pushing your aircraft down.

 

[leviterande]

When you remove the air from the top, where do you put it? If your answer is "lower", you're pushing air down. If your answer is "higher", you're pushing your aircraft down.

Sure, when you remove the air above you may guide it down and that won't nearly give as much downwash as a helicopter. you can push the air sideways instead and still get lift from the lower pressure..

you can either press more air below to go up or remove more air above to go up, that is simple and you will ofcourse have the pressure differntials in precents.. All aircrafts today gain lift from pure "pushing air down" i.e about 90precent of the lift is at least from that air going down.

But if you create a small partial vacuum above you just let the "atmospheric presure" push you. These are proven facts, no more.

Furthermore there was a very interesting project going on in the University of Houston with the Ph.Ds Michael Goldgarbageck and Fazle Hussain that were working in that direction. By creating a partial vacuum ahead with a strong tornado air current and letting the normal atmospheric below pushing up. Fazle Hussain is one of very few who won the prize for being a very brilliant Engineer. Unfortunately Michael Goldgarbageck died in 1997 and the project was shut down. they had a small prototype of 20cm that created 4kg of thrust.
The thrust direction and exit airlow are in the same direction! I have verified the directions of the airflows

 

[magpies]

All you really need is two fans pushing air in the opposite direction next to each other. Is this basicaly what your talking about doing?

 

[Cyrus]

As a person that does VTOL, all I have to say is......

 

[leviterande]

As a person that does VTOL, all I have to say is......

all I want to do is to create a partial vacuum above an aircraft rather than increasing the pressure many times beyond the atmospheric beneath an aircraft. I am sure that once we found a solution to efficiently do that, many problems will end. but ... how long is it going to take.

Just think about this: 1sq. meter holds 10 tons of air pressure on both sides. airplanes, helicopter etc. add even more pressure beneath to fly. What if we could reduce the air pressure just a little, say a 0.5 precent on say a 25 sqm area. You would get lots of thrust , about 1,25 tons or 2780 lbs. There just must be someway of relatively efficiently lowering it and the University of Houston were doing it. One of the main obstacles is the obvious passion of air to raise super sonically from a high pressure zone to lower pressure zone. If we were to creat a boundary or limiting wall for that air maybe there is an option. But here I am repeating and thinking about the Coanda effect by Henri Coanda, I know it is utterly ineffcient since you need pressurized air which is very inefficetly produced. I still don't understand the effect itself. Therefor I like to leave names for things and effects and just watch and experiment.

Obviously if all the coanda effect was to do for us was to just "curv" the air and its inertia down , it would be a very bad ineffficient way to propell anything and that is due to the known laws, conservation.
BUT! I am interested in what the Coanda effect brings with it and not the air it pushes downward. high speed airstream creates a very low pressure zone and nearly close to being a partial vaccum.

As said if I was interested into flying like aircrafts today I would go for the most efficient rotorblade design.

 

[Cyrus]

all I want to do is to create a partial vacuum above an aircraft rather than increasing the pressure many times beyond the atmospheric beneath an aircraft. I am sure that once we found a solution to efficiently do that, many problems will end. but ... how long is it going to take.

Just think about this: 1sq. meter holds 10 tons of air pressure on both sides. airplanes, helicopter etc. add even more pressure beneath to fly. What if we could reduce the air pressure just a little, say a 0.5 precent on say a 25 sqm area. You would get lots of thrust , about 1,25 tons or 2780 lbs. There just must be someway of relatively efficiently lowering it and the University of Houston were doing it. One of the main obstacles is the obvious passion of air to raise super sonically from a high pressure zone to lower pressure zone. If we were to creat a boundary or limiting wall for that air maybe there is an option. But here I am repeating and thinking about the Coanda effect by Henri Coanda, I know it is utterly ineffcient since you need pressurized air which is very inefficetly produced. I still don't understand the effect itself. Therefor I like to leave names for things and effects and just watch and experiment.

Obviously if all the coanda effect was to do for us was to just "curv" the air and its inertia down , it would be a very bad ineffficient way to propell anything and that is due to the known laws, conservation.
BUT! I am interested in what the Coanda effect brings with it and not the air it pushes downward. high speed airstream creates a very low pressure zone and nearly close to being a partial vaccum.

As said if I was interested into flying like aircrafts today I would go for the most efficient rotorblade design.

I'll entertain some calculations.

 

[Phrak]

I don't think so. You may call it as fancy as you want, but you are basically dealing with momentum conservation - for the aircraft to go up enough air must go down.

Lift = dp_y/dt is really the crux of it, isn't it? As long as the source of dp_y/dt is the fan, the skirt doesn't really add anything beyond novelty, does it?

Yet, I still wonder how some variation in this basic idea can be exploited

 

[russ_watters]

all I want to do is to create a partial vacuum above an aircraft rather than increasing the pressure many times beyond the atmospheric beneath an aircraft. I am sure that once we found a solution to efficiently do that, many problems will end. but ... how long is it going to take.

Well, obviously, it is many times more effective to increase the pressure "many times beyond atmospheric beneath" the airplane than to decrease the pressure by 1x atmospheric above! "Many times" is many times greater than 1x!

Sure, when you remove the air above you may guide it down and that won't nearly give as much downwash as a helicopter.

No, that would give you...a helicopter! That's what a helicopter does: it takes air from above it and pushes it down.

you can push the air sideways instead and still get lift from the lower pressure..

If you're going to move the air, why would you want to move it in a direction that isn't going help you any?! It will take more energy to change the direction and move it sideways than it would to just keep it moving down!

isn't the air compressor even less efficient than steam boiler?, in developing pressurized air.

That's actually a little bit of a complicated question, since pressurized steam will start to condense when you blow it through a nozzle (which air won't). But what isn't complicated is that while a gas turbine engine needs fuel, a boiler needs fuel and water, so there couldn't possibly be a power vs mass efficiency improvement from such a scheme.

Just think about this: 1sq. meter holds 10 tons of air pressure on both sides. airplanes, helicopter etc. add even more pressure beneath to fly. What if we could reduce the air pressure just a little, say a 0.5 precent on say a 25 sqm area. You would get lots of thrust , about 1,25 tons or 2780 lbs. There just must be someway of relatively efficiently lowering it and the University of Houston were doing it. One of the main obstacles is the obvious passion of air to raise super sonically from a high pressure zone to lower pressure zone. If we were to creat a boundary or limiting wall for that air maybe there is an option. But here I am repeating and thinking about the Coanda effect by Henri Coanda, I know it is utterly ineffcient since you need pressurized air which is very inefficetly produced. I still don't understand the effect itself. Therefor I like to leave names for things and effects and just watch and experiment.

Forget the calculations, cyrus - leviterande you need to think about this a litte more critically. You're saying some things that are obviously self-contradictory.

 

[leviterande]

Well, obviously, it is many times more effective to increase the pressure "many times beyond atmospheric beneath" the airplane than to decrease the pressure by 1x atmospheric above! "Many times" is many times greater than 1x!
No, that would give you...a helicopter! That's what a helicopter does: it takes air from above it and pushes it down. If you're going to move the air, why would you want to move it in a direction that isn't going help you any?! It will take more energy to change the direction and move it sideways than it would to just keep it moving down!
That's actually a little bit of a complicated question, since pressurized steam will start to condense when you blow it through a nozzle (which air won't). But what isn't complicated is that while a gas turbine engine needs fuel, a boiler needs fuel and water, so there couldn't possibly be a power vs mass efficiency improvement from such a scheme. Forget the calculations, cyrus - leviterande you need to think about this a litte more critically. You're saying some things that are obviously self-contradictory.

maybe i sound like that because it is a complicated matter but have you heared of the coanda craft or the Vortex thruster by the University of Houston for example? there are other ways to fly up than the airplanes do. and it is not about cathode rays. . as said it is a complicated matter that hardly many experienced inventors, scientests, enginners ever discuss to ultilise.. the problem is simple to define. we need to find a way of lowering the pressure above instead of keeping pushing the air down . when you do that correctly efficiently you will have a much more efficient craft that has hardly any complicated moving parts like a helicopter.

the Vortex thruster was done because of the swirling vortex, so I think if we need anything to work on that principle we need to go from there. and yes it is more effective to increase the pressure below because people have done so in years and they never tried to look in another direction for a better solution. I believe we are humans and not animals and yes we can copy flying animals but we can also copy nature in many other ways. Tornados is a small example"If you're going to move the air, why would you want to move it in a direction that isn't going help you any?! It will take more energy to change the direction and move it sideways than it would to just keep it moving down! "
i was just saying that just to show the point .. my point is that the net lift component will be derived from the lower pressure above and only a small portion or non of the lift is derived from the air pushed down since this will not work like a helicopter

 

[Borek]

Let's say we have a mass m object hanging in the air.

Let's say we have created vacuum above.

Object starts to move up.

It has a vertical speed v.

It has a momentum mv.

Momentum can't be created out of nothing, momentum is conserved. If the object has momentum mv, something else must have momentum -mv.

Where is this something?

Please don't repeat agin that this system works differently, momentum conservation is universal and holds regardless of what and how you are doing.

 

[leviterande]

I believe there are misunderstandings here... I mean between us. But no problem if there could be no point in posting more.. I just wanted to say I didnt negate the conservation of momentum

 

[edward]

I believe there are misunderstandings here... I mean between us. But no problem if there could be no point in posting more.. I just wanted to say I didnt negate the conservation of momentum

First of all WELCOME to the forum.

Using steam is a novel idea. There are a number of devices, mostly saucers, currently using the Coanda effect. The ones I have read about and seen videos of have used either compressed air or CO2.

Steam should work as well as any fluid. Without going into technical reasons ,I do see some possible problems with weight and water condensation.

Here are a couple of links you may be interested in.

http://www.meridian-int-res.com/Aeronautics/Coanda.htm


Coanda effect patents U.S. patents:

http://www.rexresearch.com/coanda/1coanda.htm

 

[minger]

Recall the full conservation of momentum equation, which we derive from Newton's 2nd law. Which states that mass times acceleration is the sum of all forces, which include both surface and body forces. Surface forces include both momentum and pressure terms, e.g. for a 1d system:
$$\frac{\partial(\rho u)}{\partial t} + \vec{\nabla}\cdot(\rho u\vec{V}) = -\frac{\partial p}{\partial x} + \mbox{Shear Forces} + \mbox{Body Forces}$$
So, if one assumes steady state, such that the object is moving vertically upwards, and we neglect viscous shear forces and body forces such as gravity, we get:
$$\vec{\nabla}\cdot(\rho u\vec{V}) = -\frac{\partial p}{\partial x}$$

We know that for lift, we need a spatial change in pressure. That's how you plan on creating lift, through pressure, not through deflection of fluid. This means that for a pressure gradient to exist, there needs to be a velocity gradient.

As said before, there are few actual laws that physicists abide by, and this is one. So, just to clarify, in order to have a pressure gradient, then yes, there needs to be "air down".

 

[Cyrus]

Recall the full conservation of momentum equation, which we derive from Newton's 2nd law. Which states that mass times acceleration is the sum of all forces, which include both surface and body forces. Surface forces include both momentum and pressure terms, e.g. for a 1d system:
$$\frac{\partial(\rho u)}{\partial t} + \vec{\nabla}\cdot(\rho u\vec{V}) = -\frac{\partial p}{\partial x} + \mbox{Shear Forces} + \mbox{Body Forces}$$
So, if one assumes steady state, such that the object is moving vertically upwards, and we neglect viscous shear forces and body forces such as gravity, we get:
$$\vec{\nabla}\cdot(\rho u\vec{V}) = -\frac{\partial p}{\partial x}$$

We know that for lift, we need a spatial change in pressure. That's how you plan on creating lift, through pressure, not through deflection of fluid. This means that for a pressure gradient to exist, there needs to be a velocity gradient.

As said before, there are few actual laws that physicists abide by, and this is one. So, just to clarify, in order to have a pressure gradient, then yes, there needs to be "air down".

That's a very basic equation with too many assumptions for any practical utility, but it illustrates the point none-the-less.

Edit: I think this is a case where Momentum theory and/or BEMT illustrates the point better here because that's the standard in the VTOL world. Anyways, it is nice to see a fluid element approach providing similar results.

 

[FredGarvin]

 

[Cyrus]

I see your , and raise you a :uhh: :)

 

[minger]

That's a very basic equation with too many assumptions for any practical utility, but it illustrates the point none-the-less.

If by too many assumptions you mean assuming the fluid is a continuum, and the mean free path between molecules is small.

Other than that I've simply neglected the viscous shear forces, and the body forces (e.g. gravity, electrical, magnetic).