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Wind / Re: Active Pitchcontrol
« Last post by mbouwer on Today at 03:15:36 AM »
Blade suspension mounted (+ 4 magnets  20 x 10 x 2 )
Now the blade yaw bearings.
Hydro / Re: Fish-way using low head hydro turbine
« Last post by Natreely on March 29, 2017, 10:24:10 PM »
With guide-lines, guide-points & unneeded lines deleted, with rough flow lines and colours added the two rotation tanks of Compact Fish-Way Hydro design will look something like this:

Southern Hemisphere version -–-Compact Fish-Way Hydro--- Northern Hemisphere version

Next Post, we will detail design aspects of the resting pool underneath the turbine & outlet design, before then progressing into turbine design and some interesting new research which has changed the blade shape.
Rgds, Nat
Hydro / Re: Fish-way using low head hydro turbine
« Last post by Natreely on March 29, 2017, 10:07:46 PM »
3.   Rotation Tank Geometry – with Sketchup but users of other CAD apps should be able to follow what’s happening.
Now to give an example of drawing the tank. With the constraint that having done steps 1 & 2, lined up the available volume of flow with the available head in the spreadsheet (most recent version 5 posted in reply #14 above), giving us the orifice diameter from the tank diameter. This is the Compact version mentioned in the last post, which we will use in this example. Now a summary of the dimensions we are designing for:
0.75m Height of vortex with turbine (Hvt)
5.88m average diameter of tank
0.88m diameter orifice
inlet having: 0.75m height of water, 0.7m wide, 0.0062 slope, Manning’s 0.015 unfinished concrete, resulting in the velocity 0.91m/s at Q of 480 l/s
Coarse inlet screen of vertical rods having 0.15m spaces
Sliding stop gate on inlet
Fail-safe counter-weighted bottom-hinged weir (flat with river-bed in flood events)
Drawing in the correct order helps give an accurate sketch. The extra radiating lines in this picture are only lines showing the axis of symmetry, not lines we are using, as we are only drawing a 2-dimensional plan for now.
Draw a circle for the orifice 0.44m radius
Calculating tank inner wall radius plus half of the inlet width 2.94 + 0.35 = 3.29
Draw the inlet width: a straight line from 3.29m towards the centre for 0.7m on the left side of the orifice if you are in the southern hemisphere or on the right if you are in the north, or you can just draw for the opposite hemisphere then flip the whole object along the axis. Optionally you can draw a 2.94m radius circle to compare with the area but this tends to get in the way later.
Using the protractor draw guide lines radiating from the centre in 15 or 7.5 degree increments depending on the accuracy you wish for (24 or 48 pie slices). The first guide line should be on top of your inlet width line. With the protractor tool in Sketchup clicking on the marks inside the protractor gives 15 degrees so it was easier to do this completely, then go back and do it again using the mid-way point between to insert extra guidelines.
Divide the width of the inlet by the number of slices you are using: 0.7 / 48 = 0.01458333
Hit m+ on the calculator to store this in the memory. Working in the direction of the flow, the next guideline after the inlet width line use the tape measure from the centre to mark a guide point at 3.29 – mR (memory recall) = 3.2754 leaving this on the screen, so for the next guide point you can minus the mR again. Keep rounding to 2 decimal places, but leave the accurate number on the calculator so that by the time you get around the tank, you should be exactly at the other end-point of the inlet width line.
Join the guide points together with the line tool.
With the tape measure a guide point 0.05m extending outwards from the inlet width line.
From this new guide-point realign the wall with the draw-line tool, to the second guide-point in the direction of the flow.
Extend this new line straight at least one metre from the original inlet width line.
Draw a parallel line to this at the distance of the inlet width.
Draw the gate section and wall thickness offset from the water’s edge.
Including the stop-gate, a distance of at least 1m, at the prescribed width & slope is needed to control the flow of volume per second, at the prescribed velocity per second. You can now delete guides and unwanted lines from the design.
Rgds, Nat
Wind / Re: Power Furling Revisited
« Last post by DamonHD on March 29, 2017, 07:14:53 PM »
FWIW I like to have the *simple* binary on/off option as a backstop, but then work some finesse in proportionally when I can do so and the system is well within normal operational limits.

But make the fallback simple and robust and you'll scarcely care if the proportional bit is working!


Wind / Re: 10ft sections for tower?
« Last post by Harold in CR on March 29, 2017, 03:22:58 PM »

 If that pipe has threads, do NOT use them as the joint. You should get pieces of the next size larger that will just fit over what you have, and TACK weld them to the iron pipe. Welding all the way around will make it weak same as the threads. This from an EX turbine installer, 4KW and less.

 You will need 3 guys per tower leg, one in the middle of each section and one at the joint, MINIMUM. This especially for raising. Center support guy is CRITICAL.
Wind / Re: 10ft sections for tower?
« Last post by SparWeb on March 29, 2017, 12:59:57 PM »
FYI, the photo attached above is for a big Bergy on a free-standing tower.
The foundation for a guyed tower can be much much smaller.
Wind / Re: Power Furling Revisited
« Last post by SparWeb on March 29, 2017, 12:57:56 PM »
Not necessary to use the actuator in an ON/OFF manner either.
Could be driven proportionally, with feedback, to throttle the turbine at times of high wind + full battery + no need for diversion.
Maybe more complicated than you need!
Yes the voltage says at power point.  The load varied a lot through those conditions yesterday.  At the end of the day when I checked the load voltage was 18  the panels130.  Just have one fet operating off pin #3 it is hooked to a 750 watt  240 volt baseboard heater and the fet  is only warm.  Going to hook up another heater that is the same to operate off pin #11 with its own fet.  Have not done any adjusting yet,  could use some help with that.
I am going to take one of the panels out of series and put it back in parallel. That will drop
the voltage  by almost 40 volt. Will the code have to be changed ?
Wind / Re: Active Pitchcontrol
« Last post by mbouwer on March 29, 2017, 09:09:09 AM »
There are many things about the generator I would like to discuss as for example the number and shape of the magnets.
On the circumference of the generator-ring I could mount 160 magnets of 4 mm wide.

In the meantime I can make the other components like the blade suspension.
So, does it actually seem to hold the voltage at power point?  Are the FET running cool.  How big is the load?  Did you do anything to adjust it?
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