Sciencey odd question just occured in my daily musings...

[fuzzy]

i can see the length of pipe can reduce flow rate due to friction losses but does it reduce pressure? i doesnt when standing as the pressure will be equal on all surfaces presuming it to be horizontal.

but the thing my head struggles with, as well as chinese (the language no the food) is if the pipe was 25 miles long and you put a very small pump on it wouldnt get to the end would it? the weight of water would eventually get to much, so i presume yes length affects pressure???????

 

[unguided1]

i can see the length of pipe can reduce flow rate due to friction losses but does it reduce pressure? i doesnt when standing as the pressure will be equal on all surfaces presuming it to be horizontal.

but the thing my head struggles with, as well as chinese (the language no the food) is if the pipe was 25 miles long and you put a very small pump on it wouldnt get to the end would it? the weight of water would eventually get to much, so i presume yes length affects pressure???????

and dont forget temperature, as water expands and contracts with different temperatures this can also affect standing pressure

 

[WaterTight]

And if that's true then you could theoretically have a pipe where at one point enters mains pressure water and at the other end, because of it's length, no water comes out?

And if that were calculated exactly, if you then took your pipe slice and shaved off an inch, it would start to pour out.

 

[WaterTight]

Temperature, friction, these are all factors. But for my experiment I'm pretending there are no other factors involved. So the pipe is made of an alien substance which is frictionless and the pipe is in a place with no fluctuating weather / temp conditions.

 

[fuzzy]

lol, i suppose that is true, if its not, we can connect the mains to a pipe and let it travel the circumference of the world? we could sit a pod or tram on top of it and have free travel

we not only sorted out water pressure but global travel and carbon footprints also

 

[unguided1]

I aint shaving an inch off nafink that releases water, I aint got enough as it is!!!!!!

 

[fuzzy]

Temperature, friction, these are all factors. But for my experiment I'm pretending there are no other factors involved. So the pipe is made of an alien substance which is frictionless and the pipe is in a place with no fluctuating weather / temp conditions.

where is this place water tight, its as if your making it up!!!

 

[fuzzy]

I aint shaving an inch off nafink that releases water, I aint got enough as it is!!!!!!

Look, if he wants to shave an inch off he can shave an inch off ok!

 

[unguided1]

Woops OK fuzzy, as long as it aint Mine!!!!!

 

[fuzzy]

its his inch, give somebody an inch..................................................

 

[ecowarm]

It soooo simple

[h=3]Flow in Pipe[/h]For flow in a pipe or tube, the Reynolds number is generally defined as:[SUP][6[/SUP]

where:

• D[SUB]H[/SUB] is the hydraulic diameter of the pipe (m).
• Q is the volumetric flow rate (m[SUP]3[/SUP]/s)
• A is the pipe cross-sectional area (m²).
• 
  is the mean velocity of the object relative to the fluid (SI units: m/s)
• μ is the dynamic viscosity of the fluid (Pa·s or N·s/m² or kg/(m·s))
• ν is the kinematic viscosity (ν = μ / ρ) (m²/s)
• 
  is the density of the fluid (kg/m³)

 

[fuzzy]

are you really reynolds ecowarm?

 

[diamondgas]

Are we getting volume mixed up with pressure? It's a common one!!

If you had a 25 mile piece of pipe totally filled with water and you pushed your finger in one end I'd expect the same amount of water to be displaced at the other end! With minimal resistance yeh? It wouldn't be solid, it's a liquid, they act in different ways, it's mass isn't a factor if gravity is equal throughout it's length.... But like a syringe or piston.

A pump works on moving water using centrifugal force, it doesn't 'push' or 'pull' it spins and throws water about, sucks it up the middle and throws it out the ends of the impellar! There's a limit to how much mass it can move yeh?

 

[fuzzy]

Are we getting volume mixed up with pressure? It's a common one!!

If you had a 25 mile piece of pipe totally filled with water and you pushed your finder in one end I'd expect the same amount of water to be displaced at the other end! With minimal resistance yeh? It wouldn't be solid, it's a liquid, they act in different ways, it's mass isn't a factor if gravity is equal throughout it's length.... But like a syringe or piston.

A pump works on moving water using centrifugal force, it doesn't 'push' or 'pull' it spins and throws water about, sucks it up the middle and throws it out the ends of the impellar! There's a limit to how much mass it can move yeh?

that made my laugh very very much, the thought of one of us running 25 miles of pipe, leaving one of us at one end while the other went to the start and push the water with a finger, lol

we will have to do this or this thread will never come to a conclusion!

how much does 25 miles of 22mm water weigh?

 

[diamondgas]

Hey we're all scientists now!! :rofl: