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John M
Lv 7
John M asked in Science & MathematicsPhysics · 1 decade ago

force of water in reduced pipe?

I'm hoping to get some advice on an idea I have about moving some water uphill from a fast moving river. I'd like to make something simpler than a hydraulic ram, basically a series of gradually smaller diameter pipes, to move some water from the river up to a cabin, about 20' above the river and maybe 40' in from the faster moving current. Would the physics of something like that work, creating enough force to move a smaller stream of water out of the river and up to the cabin, ending in 1" or even a 1/2" pipe at the cabin? I want to fill the dog's water dishes, boil water for cleaning up, and have a flow of water for rinsing things off. I don't need much pressure at the cabin, just enough to get a flow of water to fill containers would be great.

My physics on this are rusty. Any ideas?

Update:

Is 8psi practical from a fast flowing river current? I recall that narrowing the diameter of the pipe will speed the flow of water, right? Does that do me any good in terms of the lift too? If I get a 5" diameter or larger pipe full of fast moving water, and choke it down, won't it give me some significant pressure?

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  • 1 decade ago
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    I'm hoping to get some advice on an idea I have about moving some water uphill from a fast moving river. I'd like to make something simpler than a hydraulic ram, basically a series of gradually smaller diameter pipes, to move some water from the river up to a cabin, about 20' above the river and maybe 40' in from the faster moving current. Would the physics of something like that work, creating enough force to move a smaller stream of water out of the river and up to the cabin, ending in 1" or even a 1/2" pipe at the cabin? I want to fill the dog's water dishes, boil water for cleaning up, and have a flow of water for rinsing things off. I don't need much pressure at the cabin, just enough to get a flow of water to fill containers would be great.

    My physics on this are rusty. Any ideas?

    This problem is similar to a ball rolling up an incline plane!

    As the ball rolls upward, its kinetic energy is converted into potential energy.

    The initial kinetic energy of the water is determined from the velocity of the water in the river.

    The increase of potential energy = mass * g * height

    g = 9.8 m/s^2

    height = 20 ft * 12 in/ft * 2.54 cm/ in ÷ 100 cm / m = 6.096 m

    The increase of potential energy = mass * 9.8 * 6.096 = mass * 59.7408

    The decrease of KE = ½ * mass * (Initial velocity*2 – Final velocity^2)

    ½ * mass * (Initial velocity*2 – Final velocity^2) = mass * 59.7408

    divide both sides by mass

    ½ * (Initial velocity*2 – Final velocity^2) = 59.7408

    Initial velocity*2 – Final velocity^2 = 2 * 59.7408 = 119.4816

    Let’s assume that you want the velocity of the water at the cabin to be 1 m/s.

    Initial velocity*2 – 1^2 = 119.4816

    Initial velocity^2 = 119.4816 + 1^2 = 120.4816

    Initial velocity = √120.4816 = 11 m/s

    In feet/ second, Initial velocity = 11 m/s * 3.281 ft/m = 36.091 ft/s

    In miles per hour, Initial velocity = 36.091 ft/s * 3600 s/hr ÷ 5280 ft/mi = 24.6075 mph

    If the velocity of the river = 24.6075 mph, the velocity of the water at the cabin = 1 m/s = 3.281 ft/s

    If the velocity of the river is less 24.45 mph, the water will not have enough energy to flow uphill 20 ft.

    And the turbulence inside the pipe also decreases the kinetic energy as the water flows uphill.

    To decrease the turbulence inside the pipe, you should use the largest radius pipe all the way from the river to the cabin. Then reduce the pipe size at the cabin.

    If you have some 10 ft sections of 3 inch PVC pipe, you could build the pipe line and determine whether the water will flow up the hill!

  • ?
    Lv 7
    1 decade ago

    Of course just by changing pipe diameters won't send water uphill. And to make water move UP {against gravity} a distance of 20 ft THAT takes a pressure over 8 psi. Work must be done on the water at the lower level to lift it to the cabin level. So some kind of water lift {pump?} device must be used.

  • Anonymous
    1 decade ago

    You can't get water to flow uphill! You will need at least 8.66 psi at river level to lift the water the 20 feet to the cabin. Piping losses would require additional pressure. It might be possible to use the kinetic energy of the river to power a pump usine a turbine device connected to a pump. The Dutch have used windmills for years to solve a similar water transfer problem. You might want to consider a water storage tank elevated above the cabin to provide better supply vs demand.

  • Anonymous
    5 years ago

    We are using a truck radiator, an axial flow fan(1/3 hp), a 300 liter buffer tank, a 1/2 hp hot water centrifugal pump, and an old British Railways non-rusting formulation for the coolant for a similar purpose for a 24 KW water distilling plant. This has been working for years without any breakdown. We have since been duplicating this wherever needed. Incidentally the water for condenser cooling need not be very cold. Our inlet temperature is about 60 deg C and the out let about 75 to 80.

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