Can you move water vertically without a pump?

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  • #1
karamss
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Hi
I would like to design a water fountain/waterfall and want to know if i can pump water upward without using a pump.
Perhaps using gravity and pressure.

My planned size would be between 1 foot to 10 feet.


Thanks
 

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  • #2
Baluncore
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I would like to design a water fountain/waterfall and want to know if i can pump water upward without using a pump.
By definition you cannot "pump" water upwards without a "pump".

To make a fountain you must add kinetic energy to the water.
That KE is turned into potential energy as the water rises through the air.
All that energy is lost as the water falls back down.
So long as a fountain operates it wastes energy.
So where does that energy come from ?

To accelerate water and so give it KE requires a pressure.
That pressure usually comes from a pump or an elevated source of water.
Where will the water for the fountain come from ?
 
  • #3
some bloke
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As said above, you need to put energy into raise the water to make your waterfall work.

I am going to assume that by "Pump" you mean an electric pump, in which case there are ways to raise water without just connecting an electric pump to it.

You could use a chain with scoops or an archimedes screw to raise the water, but I suspect that the issue is in the electricity, not the pump itself.

Perhaps the best option for you would be a solar panel (assuming that this is outside) or to use an electric pump (if it's inside). If it's situated near to a river or stream, a waterwheel could power a pump. You could also use a convection current from a heat source such as a wood burner to naturally pump the water up (hot water rises).

Unfortunately, it's not possible to create a perpetual fountain without any energy input!
 
  • #4
anorlunda
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It may be a matter of semantics, but a hydraulic ram pump might do what you are asking about. It does not need an external motor or driving force. The energy comes from a water stream. So is it a pump or not a pump?

From the Wikipedia article:
A hydraulic ram, or hydram, is a cyclic water pump powered by hydropower. It takes in water at one "hydraulic head" (pressure) and flow rate, and outputs water at a higher hydraulic head and lower flow rate. The device uses the water hammer effect to develop pressure that allows a portion of the input water that powers the pump to be lifted to a point higher than where the water originally started. The hydraulic ram is sometimes used in remote areas, where there is both a source of low-head hydropower and a need for pumping water to a destination higher in elevation than the source. In this situation, the ram is often useful, since it requires no outside source of power other than the kinetic energy of flowing water.
 
  • #5
russ_watters
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It may be a matter of semantics, but a hydraulic ram pump might do what you are asking about. It does not need an external motor or driving force. The energy comes from a water stream.
A separate water stream.
So is it a pump or not a pump?
Definitely a pump.
 
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  • #6
karamss
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By definition you cannot "pump" water upwards without a "pump".

To make a fountain you must add kinetic energy to the water.
That KE is turned into potential energy as the water rises through the air.
All that energy is lost as the water falls back down.
So long as a fountain operates it wastes energy.
So where does that energy come from ?

To accelerate water and so give it KE requires a pressure.
That pressure usually comes from a pump or an elevated source of water.
Where will the water for the fountain come from ?
from an elevated source of water. maybe hit a wheel at the bottom and that wheel will be used to elevate water back up again
 
  • #7
Baluncore
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from an elevated source of water. maybe hit a wheel down and that wheel will be used to elevate water back up again
If the water is from a pipe with a pressure head, then you only need a nozzel to make a fountain. The hydrostatic pressure will be sufficient to drive the fountain.
At what elevation is your water supply ?
 
  • #8
karamss
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As said above, you need to put energy into raise the water to make your waterfall work.

I am going to assume that by "Pump" you mean an electric pump, in which case there are ways to raise water without just connecting an electric pump to it.

You could use a chain with scoops or an archimedes screw to raise the water, but I suspect that the issue is in the electricity, not the pump itself.

Perhaps the best option for you would be a solar panel (assuming that this is outside) or to use an electric pump (if it's inside). If it's situated near to a river or stream, a waterwheel could power a pump. You could also use a convection current from a heat source such as a wood burner to naturally pump the water up (hot water rises).

Unfortunately, it's not possible to create a perpetual fountain without any energy input!
yes i want to know if i can use a mechanical pump rather than an electrical one given the descriptions above.

it would be a design betseen 1 to 10 feet high

i plan to add a water resouvir at the top that will be used to cycle water through
 
  • #9
karamss
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If the water is from a pipe with a pressure head, then you only need a nozzel to make a fountain. The hydrostatic pressure will be sufficient to drive the fountain.
At what elevation is your water supply ?

it would be a design between 1 to 10 feet high
i plan to add a water resouvir at the top but do not know if id be able to cycle water using the water fall energy
 
  • #10
Baluncore
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i plan to add a water resouvir at the top but do not know if id be able to cycle water using the water fall energy
The energy is lost in a fountain, so you cannot recycle the energy and use it to pump water back up to the reservoir. That would be perpetual motion, which is impossible.
 
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  • #11
gmax137
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but do not know if id be able to cycle water using the water fall energy
No, you can never use the falling water to get as much water back up into the reservoir as is falling. If I understand the question.

The fountains in Rome run continuously, but that is because the rainfall in the mountains runs through the aqueducts to keep the reservoirs full.
 
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  • #12
karamss
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The energy is lost in a fountain, so you cannot recycle the energy and use it to pump water back up to the reservoir. That would be perpetual motion, which is impossible.
thanks a lot. i will look into the perpetual motion.
 
  • #13
karamss
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No, you can never use the falling water to get as much water back up into the reservoir as is falling. If I understand the question.

The fountains in Rome run continuously, but that is because the rainfall in the mountains runs through the aqueducts to keep the reservoirs full.
yes ofcourse the water will be lost in many ways. but that is not a problem if i want the water stream to go for a set amount of time. but i assume that's not the only problem?. thanks a lot for the insight about the romanic aqueduct mechanics!
 
  • #14
anorlunda
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if i want the water stream to go for a set amount of time.
For a set amount of time, you can have a water tank on a floor above, and fill the tank by carrying buckets.

Just remember that water is heavy, so keep the tank small.
 
  • #15
karamss
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The energy is lost in a fountain, so you cannot recycle the energy and use it to pump water back up to the reservoir. That would be perpetual motion, which is impossible.

hi i looked up perpetual energy and its not what i aim for
my apology i will try to clarify

say i had a 5feet high object with a water reservoir at the top and at the bottom. the water is raised up with an epump and then falls down.

if i remove the epump is there a way to make this work in a similar way
 
  • #16
russ_watters
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hi i looked up perpetual energy and its not what i aim for
my apology i will try to clarify

say i had a 10feet high object with a water reservoir at the top and at the bottom. the water is raised up with an epump and then falls down.

if i remove the epump is there a way to make this work in a similar way
Other than a pump with a different power source, no.
 
  • #17
karamss
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Other than a pump with a different power source, no.
well yes using gravity for example
 
  • #18
anorlunda
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say i had a 10feet high object with a water reservoir at the top and at the bottom. the water is raised up with an epump and then falls down.

if i remove the epump is there a way to make this work in a similar way
Yes. Move the bottom reservoir much higher than the top. Move it to the next floor or the roof (weight permitting).

Edit: But it only works once until the top floor reservoir runs out of water. It does not return the water in a closed circuit.
 
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  • #19
karamss
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Yes. Move the bottom reservoir much higher than the top. Move it to the next floor or the roof (weight permitting).

Edit: But it only works once until the top floor reservoir runs out of water. It does not return the water in a closed circuit.
yes i guess you can do it by making it trickle until the tank is empty.

if i had a tube set from bottom reservoir to the top reservoir and its filled with water. will the water falling from a 1 to 10feet high object have enough energy to push the water through the tube using a wheel or similar
 
  • #20
anorlunda
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if i had a tube set from bottom reservoir to the top reservoir and its filled with water. will the water falling from a 1 to 10feet object have enough energy to push the water through the tube using a wheel or similar
Um, I think I need a picture to understand what you're thinking. Can you sketch it on paper, take a picture with your phone, and post the picture here?
 
  • #21
karamss
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Um, I think I need a picture to understand what you're thinking. Can you sketch it on paper, take a picture with your phone, and post the picture here?
i don't have stuff to sketch on at the moment but let me try to clarify.
will the energy from a 1 to 10feet waterfall be enough to push water to the top from a prefilled tube given the height range. if so what tube size would retain the pressure better.

please let me know if its still not clear. thanks again
 
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  • #22
anorlunda
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i don't have stuff to sketch on at the moment but let me try to clarify.
will the energy from a 1 to 10feet waterfall be enough to push water to the top from a prefilled tube given the height range. if so what tube size would retain the pressure better.

please let me know if its still not clear. thanks again

It sounds like you are thinking of what we call a perpetual motion machine. That's against our rules here in PF to discuss that.

No, the water falling 10 feet can not create enough power to pump the same water back up 10 feet not matter what the tube size. That would be perpetual motion. It's impossible.
 
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  • #23
Tom.G
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Hi @karamss,

I think an easier way to look at this would be:

1) You have a tank of water at 10ft. elevation with a drain tube attached
2) The drain tube aims the stream of water at a waterwheel to drive a pump
3) The pump then pumps some water upward toward the 10ft high tank

A) The water flowing thru the drain tube from the high tank has a little bit of friction on the tube walls
B) The bearings for the waterwheel have a little bit of friction, as do the pump bearings
C) The water being pumped back up towards the high tank have some friction on the walls of that tube

Now, friction causes a loss of some energy from the parts that are moving. This lost energy is converted to heat and dissipates to the surroundings.

The result is some of the energy in the falling water is no longer available to pump the water back up to the high tank; it was converted to heat and lost.

So you have a choice, you can either pump a smaller amount of water to the high tank, or pump the same amount of water to a lower height.

Hope this helps!

Cheers,
Tom
 
  • #24
some bloke
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What you are requesting, by my understanding, is for the fountain to power itself. This is not feasible.

Think of the water as a ball. The ball falls down, and as it falls it is slowed down by air resistance. This is energy lost. The ball falls 10ft, and when it lands it has less energy than it did when it was 10ft. high, because it has lost some to air resistance.

This ball lands on a lever, pushing another ball of the same weight upwards. The second ball will also be slowed by air resistance, and will only reach 9ft. high.

When that ball comes down, it launches the other ball 8ft. Then 7, 6, 5, and eventually none. Because energy is lost.

To will need to put energy in from another source to boost the energy the falling ball is exerting so that the second ball can make it back up by 10ft.


With regards to your fountain, this means that the falling water will never give you enough energy to raise the same amount of water back up, because some of that energy is lost to the surrounding air. You can probably get something of an idea for this by using a water bottle and a ladle. Pour the water into the ladle, running down the inside edge so that it is redirected upwards. The water coming back up will never reach the bottle you're pouring it from.

So, you will need a power source. You will need to decide what suits your application best (solar, battery, mains, fire, water wheel, wind turbine, exercise bike, geothermal pylon, nuclear reactor, etc.) and then design your fountain with this in mind to power some sort of pump to move the water upwards.

Alternatively, you could build some form of reservoir to harvest rainwater and keep your fountain stocked with water that it higher than it. At that point, you're making something close to a natural waterfall! Provided your reservoir is large enough to carry you through the lowest average rainfall for your area, the fountain will continue to run all year round.
 
  • #25
The Fez
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There is a type of fountain that runs only on gravity called a Heron's fountain. They can actually run for quite a while without any input. As stated above, nothing can run forever, but a well designed gravity fountain can run for several minutes at least.

https://en.wikipedia.org/wiki/Heron's_fountain
 
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  • #26
rbelli1
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nuclear reactor
An RTG with a thermo-siphon would work for this application. However the water in your reservoir now all goes up eventually instead of down when using gravity.

BoB
 
  • #27
bob012345
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It sounds like you are thinking of what we call a perpetual motion machine. That's against our rules here in PF to discuss that.

No, the water falling 10 feet can not create enough power to pump the same water back up 10 feet not matter what the tube size. That would be perpetual motion. It's impossible.
The usual definition of a perpetual motion machine is that such a device not only goes through a complete cycle, but it generates useful net energy doing so. Merely returning to the same point such as a wheel spinning with no loss is not technically a perpetual motion machine. I am making a distinction between a perpetual motion machine and a machine in perpetual motion. Some things are in or virtually in a state of perpetual motion such as things in high orbit. Of course real machines have losses. So technically any machine that made up those losses with no added energy input would indeed be a perpetual motion machine. But one can minimize the losses and provide the added energy in clever and subtle ways so give the illusion of a machine in a state of perpetual motion.

James Cox invented a large self winding Grandfather clock in the 18th century. It is said the clock ran for over 100 years undisturbed and in principle could run till the parts wore out. Cox made a device to rectify the motion of a Mercury barometer and store that energy to wind the clock. His main issue is he got too much energy and broke springs till he worked out the final design.

Consider the 'drinking bird' toy. It uses a low boiling point organic liquid and evaporating water. You could see if such a liquid moving around in a sealed glass tube powered by small temperature differences could move around continuously and create the illusion of a self powered eternal water fall.

https://books.google.com/books/about/Perpetual_Motion.html?id=022yYXnS_GQC
 
  • #28
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The usual definition of a perpetual motion machine is that such a device not only goes through a complete cycle, but it generates useful net energy doing so. Merely returning to the same point such as a wheel spinning with no loss is not technically a perpetual motion machine.
Not so, according to the Merriam-Webster dictionary:
https://www.merriam-webster.com/dictionary/perpetual%20motion%20machine said:
a device inherently impossible under the law of conservation of energy that can continue to do work indefinitely without drawing energy from external sources

And Wikipedia:
https://en.wikipedia.org/wiki/Perpetual_motion said:
A perpetual motion machine is a hypothetical machine that can do work infinitely without an external energy source. This kind of machine is impossible, as it would violate either the first or second law of thermodynamics or both.
I am making a distinction between a perpetual motion machine and a machine in perpetual motion.
A faulty distinction.
 
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  • #30
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Thank you all for contributing some great replies to the OPs question.

It seems this is a good time to close this thread now.
 

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