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james overseer 2023-08-20 11:32:07    
Sir; A few questions please; #1 Did you find that the 'elastic' sails reduce the drag do to the sharp trailing edge? #2 or they work better than metal flap sails? #3 Do you have a final design that we can build 5 units and trial them with your oversight, blessing and payment. Please advise; James@EdenBlueGold.com  
Bruce lavoie 2021-05-16 08:54:58    
You should rewrite this article because TSR is valid for savonius turbines because I have built savonius wind turbines with TSR > 1.8 It's called a "sheilded Savonius".  
Guest 2021-05-16 08:52:34    
Steve 2012-11-26 16:32:47    
I don't think you are being fair to the other types of VAWTs. While yours only generates power on the downwind side, lift type VAWT blades make power all the way around, except for directly up wind and directly down wind.  
Abu Bakar 2011-12-20 01:13:45    
By experimenting with VAWT I noticed instability in the design. Your scheme with flaps provides an innovative solution to the problem. Hope to test it soon.  
Mangesh Jagtap 2011-11-08 08:39:02    
THis is really good articles. It has increased knowledge of WTG a lot.Specifically number of bades article and TSR article is very intresting.  
Tim 2011-06-20 02:16:03    
Read your section on TSR, you have the concept vaguely correct but most of the detail is a bit off. If you want to undestand HAWT you need to read about wake rotation, lift drag ratios and how these effect the optimum tsr. The problem with your drag type devices (even if you completely get rid of the drag on the upwind leg) is that the equvalent betz limit is 4/27*cd. Where cd is the coeffceint of drag on the downwind section. If cd on you downwind section is 1.5, and cd on your upwind leg is 0, which is ambitious this gives you 22% max effciency, not ideal compared to the typical range of 30-55% for HAWT's. It not really to do with how much of the wind area you touch(althought that is important) but its to do with how much you can slow the wind down while still maintaining a good flow rate thourgh the turbine. the power is equal tho the ammout of kenetic enegry taken form the wind times the flow rate.  
Admin 2010-08-15 19:59:51    
Thanks Spanner, Thank you for your encouragement. I also thank you for going great details to look at my calculations.  
Admin 2010-08-15 19:59:51    
This is the video that dave is talking about. You Be The Judge  
Admin 2010-08-15 19:59:51    
Dear Dave, I don't know where did you get the idea that I was saying that this turbine adding any power to the vehicle. Did I claim in the video that the turbine was generating power? I did not have a wind tunnel to test my turbine. So I mounted it on a truck. Rather than wind blowing at 72mph we were driving the car at 72kmh, the effect is the same. We were testing whether flaps will perform as we expected it to perform under stormy conditions and they did. Did you study all the subjects in my web site, did I ever claim something contrary to the thermodynamic first and second laws? As I mechanical engineer who instructed students in thermodynamics at reputable universities, I know what is possible and what is not. Maybe this article will help you about my background. Vortex Pairs and Vortex Loops  
dave 2010-08-15 19:59:51    
Howdy, Mechanical Engineer speaking on marketing: I saw the video of your turbine mounted on a semi, and I'm 75% sure you're aware this is not adding any power to your system except if your were driving into the wind on a windy day. So I would have moved right along web surfing if it weren't so comical. I would instead display it using a fan. As it is, it looks as though you're trying to advertise this as helping with gas mileage or some other vehicular efficiency improvement along the lines of a perpetual motion machine.  
Admin 2010-08-15 19:59:51    
Dear Faan, Thanks for your comment. Yes, the noise is an issue with this turbine and I am working on reducing the noise.  
faan 2010-08-15 19:59:51    
What about noise created by the flaps?  
Mark Mathews 2010-08-15 19:59:51    
I think your VAWT can be improved by limiting the motion of the flaps so they can't go too far backward. Try to tie them together and put a small wire stopper behind the lead flap. Also, probably the flap arrays can be larger because your frame looks pret  
Spanner 2010-08-15 19:59:51    
Hi, interesting designs. I'm very impressed with your animations and interactive calculations. I wish you all the best, and hope you continue with your excellent work, and that it leads to great success. Spanner England UK  
Admin 2010-08-15 19:59:51    
Thanks Gary, There are a couple of patents related to flap turbine. The one you send also interesting. I live in Bethlehem, PA USA.  
gary scarborough 2010-08-15 19:59:51    
us patent 4,218,183 from 1980 describes limited motion flapped windmills I would love to tr your simple designs too. I am in Canada near Toronto. Where are you?  
Phil Stahlheber 2010-08-15 19:59:51    
Howdy I'm not sure what your name is , so please forgive me for not addressing yoy properly. I am in Tehachapi CA, and am building all kinds of wind turbines. My VAWT is is a collection of thirty blades, all of which move by the acton of the wind. It is three feet in dia. and three feet tall. I am setting it up to drive a one KW DC generator. I don't know how this feedback thing works, but if you would like to compare notes and project progress, my e-mail is ( stahlheber@hotmail.com )  
alexg654 2010-08-15 19:59:51    
Very nice site!  
Mike 2010-08-15 19:59:51    
Interested in your work in Flap Turbines as I am currently putting together an Alternate Energy Fund and we are looking at investments in Solar, Wind, and Energy Storage companies. Would be interested in learning more about your developments with your fl  
Ashish 2010-08-15 19:59:51    
Hi, It's really intersting concept. I am working on improved drag type turbine and was always wondering how lift type turbine be so efficient when they hardly are in contct with gas particles. Serious analysis is needed to put forward theory of drag type  
Admin 2010-08-15 19:59:51    
Hi Justin, just send me an email to discuss details of your design. Regards  
MUHAMMAD FAROOQ 2010-08-15 19:59:51    
your animations - a great help for those who wish to advance their comprehension of systems and arrangement. My salute to you.  
Justin L 2010-08-15 19:59:51    
working on my own flap turbine atm. Not sure how to build central axle for the thing. Have you hooked up your turbine to an alternator yet to see how much electricity it can produce?  
Admin, 2010-08-15 19:59:51    
Mark, your suggestion for restricting flap movement is very good. My actual application for patent actually includes this, however my demo turbine does not have this future.  
Mark Mathews 2010-08-15 19:59:51    
pretty sturdy. I've an idea for a different type of wind energy capture machine. Power output should be huge, but will need stronger base and some mechanical motion. Need someone to help me design it.