Hydropower session notes 2
session 2 saturday May 7th 2023at the Vale
objectives for session 2 (we will not get through all this for sure... but lets try)
overall in session 2 we will be transitioning from theory to practical ideas
- equation relating water flow , fall and energy / power
- equation for a V notch meauring weir
- design for a V notch weir to install in the stream (i.e. measurements, what size)
- experiment with magnets and coils toget a feel on how motors and generators work
- work out the rotation speed needed for a bike wheel to generate its rated power
- work out rotation speed for a hoverboard wheel
- what different types of water turbine are there ?
- can we make a plan to fit the water guage and measure periodically ( webcam ?)
- can we have suggestions how to make the first water generator from the pipe and propeller and hoverboard motor
- can we have a plan on putting up the railings (should be available early next week)
- and a plan to clean out the junk from the river, and what to do with it
- the sewage also needs looking into, can we help at all with some investigation using dye etc
- encourage a couple of people to write-up on the wiki
more detail follows Just a list of ideas and activities really:
we are starting this session with most participants having atteneded our previous discussions about what is power, energy, work, why and how do we measure it, and should have some idea abourt basic quantities etc.
- Quick recap on work power energy time
- discussion with the aim of being able to quantify the amount of energy which can be taken from water flowing from a high place to a low place
so there are some quantitites to consider
the difference in height between the high place and low place , known as fall
the amount of water measured as a flow rate, i.e. amount of water in a certain time
we could use litres per second, cubic metres per hour or whatever
how much does water weigh per litre ?
What is the equation then which gives us the energy expended by an amount of water falling a certain distance, say 1 litre falling 1 metre
....................... the equation we are looking at is; here;.......................................................
we did talk about this but not in detail, and from the previous session notes (on the wiki btw)
10 (10kg) litre bucket of water at 1000 metres
[[ The potential energy of anything falling from a height is given by U = mgh, where:
- U is the potential energy in joules
- m is the mass in kilograms
- h is the height in meters
1 liter of water has a mass 1 kg and the value of g is 9.8 m/s^2. U = 10(1000)9.8 = 98000 J ]]
The amount of energy 10 L of water would have after falling 1000 m is,
98 000 J
........................................................................................................................................................
how can we put this to some use in our situation ?
i.e. how can we measure the flow rate of our stream in order to get some idea of the available energy per unit time ( i.e. power) we might be able to generate if we had a 100% efficient generator
suggestions might be buckets and guesses,
VC notch guage is a good one ( see links on the blog)
can we make one and install it, when what dow e need
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onto another subject;
how do we go about converting moving water into mechanical motion and then it electrical energy ?
This will be a playful hands-on group discussion using objects we have available, focusing on wheels of various sorts
a windmill with an electric generator (use fan from drying room for demo)
bike wheels with motors generators built-in, can we measure any voltage ?
hover-board motors can we measure any voltage
magnets and coils and home made rigs
crisp packet loudspeaker experiment
so we can get electrical energy from moving magnets and coils, how can we get the movement from the water?
Padles on wheels ( see blog pics and Matts waterwheel, also the windmill
focus on rotation speed, work out how fast it would need to rotate based on a bike doing say 10 km per hour or another suggested normal speed for a bike
and do the same for a hoverboard motor, what power rating are the motors ( search internet for spec) could we expect a similar amount of power generated if rotate at same speed ?
Wheel diameter/circumference, distance travelled in certain time etc
................................
please can someone write this up on a wiki page
eauation for water flow / head/fall and energy / power
poweer rating of bike wheel motor, and rotation speed
power arting for hoverboard wheel and rotation speed
water turbine type...
there are many different types of water turbine, used for different flow rates and heads
what are the main type s? Suggestions from the groups knowledge and internet search
also can someone write (start to write) a wiki page about this please
( how to write a wiki page discussioin maybe)
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can we make a plan to fit the water guage and measure periodically ( webcam ?)
can we have suggestions how to make the first water generator from the pipe and propeller and hoverboard motor
can we have a plan on putting up the railings (should be available early next week)
and a plan to clean otu the junk from the river, and what to do with it
the sewage also needs looking into, can we help at all with some investigation using dye etc?
