Engineneering-homemade

[Clive HartlandParticipant @clivehartland94829]

Query, is it velocity or volume to make more power? All the time I was in Africa I never saw any effort to use natural water to make leccy. Not even on white managed farms where some of them had cascading streams and reserviors. Mostly wind driven windmills to pump underground water, pumps about 1" diam. A lot of underground water was undrinkable due to dissolved salts like Floride. Not good for cattle.

Clive

[Jon GibbsParticipant @jongibbs59756]

Hi Clive,

In theory since kinetic energy is 1/2 m v^2 and mass and volume are proportional, it's better to increase the velocity than the volume by the same factor.

…but I suppose that assumes that the turbine extracting the power has the same efficiency across the range of variables. 

Jon

Edited By Jon Gibbs on 15/05/2015 15:48:17

[Neil WyattModerator @neilwyatt]

It may surprise you all to know that, in the UK, you need an abstraction licence to run a waterwheel off-line, even though you put the water straight back in the river.

Not sure about an on-line undershot wheel that didn't need a weir.

Reasons are fairly obvious if you think about what could go wrong.

Neil

[Ian S CParticipant @iansc]

It depends on the type of turbine, for a Pelton -Wheel you need velocity, a high head of water, and a small nozzle, sometimes more than one.

For a low head, a turbine such as a Francis type, this uses the volume of water, but only a few foot, metres of head, this turbine will run at a lower speed than the Pelton- Wheel.

Ian S C

[BigAlParticipant @bigal15229]

If you have a small steam nearby as a water source how about using a ram pump to get the water up to a usable level. Many years ago there was a series of articles in Model Engineer all about them.

[JasonBModerator @jasonb]

Yes my comment on costs had assumed the tap in the OP's video was on the mains.

I'm just in negotioations to buy another Monitor kit but this one was designed to run a pump jack, just need to find a free source of fuel then I can do what I like with teh water 1/3rd scale one of these

[BigAlParticipant @bigal15229]

The ram pump I was thinking of just works by water pressure. Here is a Wiki link that explains all.

http://en.wikipedia.org/wiki/Hydraulic_ram.

BigAl

Edited By BigAl on 19/05/2015 15:59:17

[Roger HartParticipant @rogerhart88496]

Apparently people did try running small turbines off the water main in the early radio days. The water companies didn't like it and used to trace the culprits using a listening stick to hear the distinctive buzzing noise.

Is there any advantage to the backshot approach other than a different direction of rotation?

[Gordon WParticipant @gordonw]

Ram pumps used to be quite common, still used in some places. The ones I have seen need a fast flowing river, and pump a small proportion of that water, so the water needs to be drinkable if that's what it is wanted for.

[Ian S CParticipant @iansc]

Using a ram to pump water to a head to generate power is almost in the class of perpetual motion, but it is an ideal way of pumping water for domestic use, or irrigation, properly set up, a ram will run for years with very little maintainance, but electricity generation requires large quantities of water. Invented by Mongophier (spelling) the French balloon guy. Getting OT.

Ian S C

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