question about fluid dynamics?
Monday, May 3rd, 2010 at
11:43 am
if i have a garden hose still half coiled up on a hose reel, and iam pumping water through it. does the pump work harder to push around the coil or not?
no- there isnt any kinks. i know the further the distance, the more torque i need. but i wondered whether the water going up hill through the coil would regain the spent energy on the downhill return.
Filed under: Hozelock Hoses
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Any kinks?
So long as there are no kinks or other areas, where the hose is being deformed, then no. For water at high pressures, it doesn’t really make any difference whether it travels horizontally, vertically, or in aloop, the pressure loss through the hose will stay the same. (unless you change the diameter of the hose or make it go around sharp bends.)
Yes it works harder because you lose energy to the heat and friction you can never regain it while going back down.
However if you have a frictionless hose then W = F*d and as long as you are going the same distance the path does not matter and you will have put into the same work.