Skip to main content
29 votes
Accepted

Why is hydro-electric power still scarce in some places?

Because most of the water is at the lowest point is can be, the ocean. Second issue is that you need quite a bit of vertical drop for water power to be a viable power source. There are DIY hydro ...
ratchet freak's user avatar
12 votes

Why is oil used as the lubricant in power generators, while water is the most available, cheapest and accessible lubricant?

Sea water is about the worst thing in the world to put in a metallic mechanical device. As noted , corrosion would be horrendous ; dissimilar metals, stray currents , etc. Wind turbine gearing is an ...
blacksmith37's user avatar
  • 6,154
10 votes

Why is hydro-electric power still scarce in some places?

There are two issues, harnessing and market. You need both to be viable. A market, makes most of the 70% of the land mass covered by water unusable, because even if you could harness the power, it ...
StainlessSteelRat's user avatar
8 votes

Why is hydro-electric power still scarce in some places?

Rivers in a flat landscape are often unsuitable because you need a height difference to make the turbine work. Let's say a 1 meter height difference is required. There are many areas where the river's ...
Hobbes's user avatar
  • 746
7 votes

How to divide the water flow into outlets with equal flow each?

Even if you had matching orifices, you might have issues with the pressure drop inside the pipes and corners. If you are really after matching flow rates, you could look into flow control valves/flow ...
NMech's user avatar
  • 24.4k
4 votes

Can a retention/detention pond and a parking-lot be constructed in the same site foot-print?

Yes, Underground Detention is a thing. That Wikipedia article even mentions placing them under parking lots. The exact method that you propose is a little different than preconstructed vaults, but it ...
hazzey's user avatar
  • 10.7k
4 votes

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

The reason why a hydroelectric generator is fundamentally different to a gas turbine is because water under pressure is not a gas, and does not change size significantly as energy is extracted from it....
Da bishop's user avatar
4 votes

How to calculate hydropower in kW without water head

If you have horizontal water flow (no head) you are extracting its kinetic energy (from its velocity) not its potential energy (from its head). So you need to know the velocity of that flow as well ...
user_1818839's user avatar
  • 1,620
4 votes

Managing water supply pressure to a building

The best method is to pressurize your tank on the upper floor, then regulate the flow as it goes down. This is because pressurizing will require active components (i.e. pumps, and other devices that ...
Mark's user avatar
  • 5,333
4 votes
Accepted

What happens to the sedimentation collected in water treatment plants?

I was part of a team of contractors to remove and spread the dried sediment from a water treatment facility - the sediment was a red cake/ powder and was spread on the fields as fertiliser.
Solar Mike's user avatar
  • 15.9k
4 votes

Why is hydro-electric power still scarce in some places?

In years past I would have been a fan of hydroelectric power but I have read1 about some of the downsides over the years. These include: Major ecological problems including blocking fish migration. ...
Transistor's user avatar
  • 10.9k
4 votes

Why is oil used as the lubricant in power generators, while water is the most available, cheapest and accessible lubricant?

Great question! Water absolutely is used as a lubricant in some power generating systems. For example many Francis style turbines use their feed water as the primary lubricant and coolant of the ...
Medievalist's user avatar
4 votes
Accepted

Why aren't these spokes radial?

Radial lacing "tortures" the spokes of the wheel because when torque needs to be transferred from the hub to the ring when accelerating (or from ther ring to the hub during braking). Radial ...
NMech's user avatar
  • 24.4k
3 votes
Accepted

Is it possible to create a sub-surface pond?

I would describe this negative incline portion of the pond as a "shelf". They are common and need to be self-supporting with a material that has compression and tensile strength; concrete and rebar, ...
ericnutsch's user avatar
  • 8,181
3 votes

Difference between static water level and water table level

Static water level refers to the level of water (in a well for example) under normal, undisturbed, no-pumping conditions. Static water level is best determined when the well has not been pumped for ...
J.Daou's user avatar
  • 503
3 votes

What happens if one pumps from municipal water supply during power outage?

It isn't just a question of air. When you put suction on a system that's normally under pressure, you're going to draw in contaminants through every available opening — leaks in underground ...
Dave Tweed's user avatar
  • 6,904
3 votes

What are these "water fountains" in the middle of a river in North Korea? (Probably also found elsewhere.)

They are merely ornamental. Near the top of the image you can see the base of Juche Tower (Google Maps), a monument in Pyongyang on the bank of the Taedong river. (the two large fountains are ...
Wasabi's user avatar
  • 13.1k
3 votes

How to divide the water flow into outlets with equal flow each?

If the head pressure is any more than just adequate, the problem is very easy. Just ensure that the bottleneck is near the points of exit, that they are of equal diameter and approximately the same ...
Corwin May's user avatar
2 votes
Accepted

Best way to get rid of turbulent flows?

Assuming you are wanting to minimize turbulence in the region of the pump, you would probably need to use flow straighteners somewhere upstream of the pump. You would have to study the optimal ...
Wes's user avatar
  • 503
2 votes

Best way to get rid of turbulent flows?

In wind tunnels usually meshes and/or honeycombs are used to reduce turbulence. However, to really achieve low turbulence it's probably not enough to add a single component to your facility. I rather ...
Robin's user avatar
  • 679
2 votes

Low cost, moderately accurate water depth measurement

Measuring water in open channels is a basic element of water conservation. With the increasing demand for improved water management techniques, there is a serious need for low-cost and accurate water-...
Kyla peter's user avatar
2 votes

What development possibilities could yet exist in water desalination?

For reverse Osmosis This site gives the minimal required energy for sea water desalination by RO as 2.78 kJ/l (fresh water), this is if you consider only the reversible process. According to ...
mart's user avatar
  • 4,791
2 votes

Open Channel Flow with no slope

My open channel hydraulics are a little rusty having ended up in project management for a few years. Assuming sub-critical flow, i.e. the Froude number is less than 1. This is reasonable unless the ...
user10240's user avatar
2 votes
Accepted

Channel or Canal?

I thought this would be easily answerable by looking at English dictionaries. But they're not as useful as I'd hoped. Channel: the bed of a stream, river, or other waterway. Nautical. a navigable ...
AndyT's user avatar
  • 3,143
2 votes

How does water sink works?

This is a simple case of communicating vessels: When water enters your sink, it raises the water level on the right side of the kink all the way up to the sink. This means that the water pressure on ...
Wasabi's user avatar
  • 13.1k
2 votes

Is there a way to make water rise from 1'st to 2'nd floor?

Add a water pump on the main floor of your house that pumps it to the second floor. Or, assuming your house is connected to a city plumbing and water system have an extension line added to the second ...
Diesel's user avatar
  • 622
2 votes
Accepted

Is there a way to reduce leaks and infrastructure damage when turning water on and off at the scale of city?

It is difficult to provide a useful answer to this question without additional information. For example, what is the system pressurization - operating psi/bars? Having installed ductile iron water ...
AsymLabs's user avatar
  • 652
2 votes

Is there a way to reduce leaks and infrastructure damage when turning water on and off at the scale of city?

The problem with older and under-maintained (this is South Africa after all) systems is that the pipes get brittle, rusted and joints fragile and the network won't be able to handle the transient ...
ChP's user avatar
  • 623
2 votes

Dew point and raining

The important point here is that rain tends to form at some significant height above ground level. When you get water droplets condensing in situ it is usually referred to as mist or fog or dew when ...
Chris Johns's user avatar
  • 15.2k

Only top scored, non community-wiki answers of a minimum length are eligible