Back at the R&D for a short time. Spent a few hours in Google Sketch up playing around with a thought or two. Then I took advantage of a piece of equipment we have at work. I didn’t utilize it to its full extent, but damned if that thing doesn’t impress the hell out of me. It’s a rather large water jet table of which my little project didn’t even cover 10% of its size. This thing is monstrous for cutting down large sheets of steel.
Anywhoos, here is a pic if what we cut out.
Brought it home and checked it on balance and it’s dead flat. Spun it up just for giggles and it spun there for quite a while with no wobble other than the typical gyro yaw precession. I used a leaf blower to spin it up faster and it impressed me further. ROFL, I am such a big kid when it comes to stuff like this.
So, yeah, it’s a hub for five blades, only this one is for a VAWT not a HAWT. I am cutting the blades from a section of sewer pipe I have left from putting in my septic system and am fabricating some struts to attach them into place. The genset is my old genny, now modified with a new stator and neodymium magnet. (Essentially a Delco stator with a permanent magnet instead coils ) .
I haven’t finished every thing yet, still cutting and balancing blades, but when completed, I plan on testing it for awhile before going whole hog and installing it. I still have the old tower base and tower sections I can use for testing and since it is a vertical unit, turbulence is less of an issue for it. (Granted, it’s still an issue,,,) I also plan on making a testing station to mount into the bed of the truck to take to the MTR strip job so I can get some serious clean winds on a mountain top.
A few points I am considering
- Blade count
- Blade width
- Blade length
- Diameter of finished unit.
Going by some of what I have learned with the HAWT units, all of these are factors; looking at the design in 3d I see that 5 blades gets the most surface area into the wind with the least amount of resistance. At least visually it seems so. Two blades will be fully catching the wind, two will be tacking while the fifth will be oposing it. So, for now, 5 seems to be the best for a small unit, but plans may change when exposed to real world conditions. Blade width is at 4″ right now because that is 1/3rd the circumference of the pipe I have. I am thinking that will give as close to a wing shape as I can hope for without heating and bending plastic. I am looking at getting some 12ga aluminium sheet and bending it for a permanent install, but for now, plastic will suffice for testing. Admittedly, 6″ would catch more wind, and that is what the original design called for, bur 4″ is what I have.(I hate to waste money). Even so, there is just as much surface area on this 4″ blade as the is on the wind grabbers on my current rig in the air. I should see some activity even if it’s not sufficient for my needs.
But that is why we have R&D, right?
I will post more as this progresses.