Mace Canute
Elite Member
I think it makes a nice bit of kinetic art.
Unique Savonius wind turbine
- Thread starter tractorgp
- Start date
- Views: 15173
I think it makes a nice bit of kinetic art.
buickanddeere
Super Member
Don't want to rain on your parade but there are those pesky laws of physics we all have to follow.
Ever wonder why wind turbine companies install 250ft tall towers and propeller type blades 100+ feet long each ? Cause they are the best performing and lowest cost per Kw hr.
The cup type fill with snow and freezing rain.
No matter what design , the turbine at best makes 1/3 of it's rated capacity because that is all the wind blows.
How many Kw hr do you plan on making with your turbine ? The amount of power depends on swept area . Your turbine would be good for about 50-60 watts in gale force winds.
If the surrounding buildings and trees are 30ft high. The turbine tower should be a minimum of 45ft and 60 ft is better.
Ever wonder why wind turbine companies install 250ft tall towers and propeller type blades 100+ feet long each ? Cause they are the best performing and lowest cost per Kw hr.
The cup type fill with snow and freezing rain.
No matter what design , the turbine at best makes 1/3 of it's rated capacity because that is all the wind blows.
How many Kw hr do you plan on making with your turbine ? The amount of power depends on swept area . Your turbine would be good for about 50-60 watts in gale force winds.
If the surrounding buildings and trees are 30ft high. The turbine tower should be a minimum of 45ft and 60 ft is better.
OP
tractorgp
Platinum Member
Can't argue with any of your comments. I expect to be capable of lighting a few LED's (should I install a little generator). Idea is to check out new concepts. Here's a photo taken a min ago showing how the tower will be situated in the pickup.
OP
tractorgp
Platinum Member
Redneck in training
Elite Member
It is worse than you say. Typical small scale turbine produces about one eighth of rated power in average location. The reason why the turbines are so large there is not a lot of energy in square foot of air stream.
OP
tractorgp
Platinum Member
Here's the latest video on the turbine. Working to get it ready for a road test. This video shows making a simple tachometer, modifying the tail braces to make more expansion room for the buckets when they are spinning at high speeds, some tower preparation work, etc. Had the turbine spinning over 500 rpm and am pleased with the results in terms of vibration. With a maximum anticipated tip speed ratio (turbine tip speed to wind speed) of 1.0 will be comfortable operating in 50 km/h winds (about 30 mph) for the initial tests with the pickup.
OP
tractorgp
Platinum Member
Made two road tests so far and nothing conclusive re operation yet. Most noticeable was the "tail wagging the turbine" effect. So I increased the size of the two yaw pieces and reduced the wagging somewhat. Yesterday I extended the tail arms and installed aluminum yaw and tilt pieces (original parts were p.t. plywood). I'm hoping this new tail will eliminate the wagging. Will do another road test when road and weather conditions permit. Here's a photo of the latest variation. Just installed 4 C-clamps to the front plate to counteract the extra length of the tail (to control the tilting action). Eventually I will get a video done up showing the road tests.
Redneck in training
Elite Member
The tail wagging is caused by eddy shedding effect caused either by eddies generated by your pickup cabin or the turbine itself. If it is your truck then you need taller mast and mount it closer to the cabin. If it is the turbine then you can place the the fins on side of the turbine or make them long enough to catch two eddies. One from left and one from right. But I think it is your truck causing it.
https://en.wikipedia.org/wiki/Strouhal_number
https://en.wikipedia.org/wiki/Vortex_shedding
OP
tractorgp
Platinum Member
Thanks for the links. Kind of think that the turbine is in a pretty good laminar flow with the current height. Also another possible contributor to the wagging might be the buffeting effect due to the the blunt front plate. Perhaps dumping wind and returning (due to tail influence) to neutral and repeating. Anyway it is interesting and will have a better idea when give this new tail a try.
OP
tractorgp
Platinum Member
OK - Just back from a road test and glad to report the wag is gone! Had a GoPro mounted on my chase vehicle but haven't processed the video yet. Now I'm in the clear to work on the augmenter and overspeed control.
