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Engineering Stack Exchange

Questions tagged [water-resources]

86 questions
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Why don't hydroelectric plants use cascades of turbines instead of single turbines?

In a gas turbine engine there're multiple sets of blades - one set after another and combustion products pass all the sets and each set of blades gets some of the power. This increases utilization of power from burning gas. Meanwhile hydroelectric…
sharptooth
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Is there a method to determine the runoff for arid areas in developing countries?

Note: this question was totally rephrased and expanded on, addressing the comments and questions posed to the first version. The de-facto standard source for runoff calculations in South Africa is the "SANRAL Runoff Manual"…
SlydeRule
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Determining RTK parameters for runoff analysis

I am examining a watershed and determining runoff using the RTK method. I basically use a 'guess and check the hydrograph' method right now. I've seen calibrators that use a mutation and convergence criteria using root mean square but I've had…
RossV
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Why is oil used as the lubricant in power generators, while water is the most available, cheapest and accessible lubricant?

The lower viscosity of water reduces friction. Besides, the water can transfer heat way better than oils. So why not use water as a lubricant in wind or hydro turbines, especially on equipment which is operating in the ocean ... It seems to be a…
Sam B
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Low cost, moderately accurate water depth measurement

tl;dr: After an extended conversation with an old-timer, I realized a few things: The single most valuable measurement for the majority of people will be water-depth-in-well. The second most valuable will be water-flow-from-well. The "bubbler"…
Peter Rowell
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Best way to get rid of turbulent flows?

I am making a testing facility for pumps. This facility has to be able to handle 500 m3/h with at little turbulence as possible. The basin itself is 5 meters long, 2,5 meters wide and 2 meters tall. The water level in the basin is kept at 1,9…
Arjo
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Why are creeks sometimes piped underground in urban areas?

I live in Melbourne, Australia and a lot of the creeks here have been diverted through underground storm water pipes. I guessed that this is because land is highly sought after for development, and a lot of these creeks have been built over, however…
user81655
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What development possibilities could yet exist in water desalination?

I am thinking mainly in $\frac{kWh}{m^3}$ and $\frac{\$}{m^3}$. In the past some decades a wide range of surprisingly efficient water desalination plants were built, mainly in desert regions (Middle East). These plants use reverse osmosis via a…
peterh
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Why is hydro-electric power still scarce in some places?

70% of the Earth's surface is covered in water, why can't a hydroelectric power plant be set up on each and every river? Is it that its too expensive? Why is electricity still a problem in countries that have abundant number of rivers? Why can't…
Sristy
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Can I seal the inside of a water well to use it as water reservoir when the well is dry?

We've had unusually dry weather and our well has run so low that we had to call in a water hauling company to refill it a few days ago. The water man told me that even though he dumped in ~ 1000 gallons, a great part of it will seep out of the well…
cannotcompute
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Is there a way to reduce leaks and infrastructure damage when turning water on and off at the scale of city?

Cape Town, South Africa is experiencing an extremely serious drought, with estimates putting April 21, 2018 as the day that the city will be forced to shut off all municipal water supplies and begin water rationing, except to essential services such…
Jonathan Rayner
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Rule of thumb maximum flow velocity of water in pipes

I have come across various values for maximum flow velocity of water in pipes. At university we were told that 2 m/s is the upper limit where flow becomes turbulent. In various planning reports I have read recently, 1 m/s is stated as the upper…
SlydeRule
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Why aren't these spokes radial?

Have a look at this water wheel (located at Hama, Syria). Most spoked wheels seem to be designed with spokes that radiate outward from the center of the hub (bicycle wheels being the notable exception). All of the spokes in this wheel are offset…
ConanTheGerbil
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How to divide the water flow into outlets with equal flow each?

I'm designing a machine that uses water to boost fish in one phase of a process. My main concern is how to split the water flow that I get from a water pump in to $N$ outlets with same flow rate. The image below shows this graphically. I need to use…
Pablo Díaz
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How do I calculate the density of seawater at different temperatures?

I need to know the difference in seawater density at 28 and 98 degrees Fahrenheit for control system synthesis. How can I calculate the density for a given temperature?
andrewhunter
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