A new type of VAWT that is easy to build

[Music] this video is about a new type of vertical axis wind turbine that i'm working on well are you going to continue to watch this this guy doesn't even know how to pronounce the word turbine turbine turbine turbine turbine oh i guess he's speaking american english sorry i interrupted this video is about a new type of vertical axis wind turbine that i'm working on and i have a proof of concept made and working which i'll show to you later in the video video and if everything works out this should be pretty simple to build so that a home builder could build it and utilize it so let's uh dig right in wind turbines basically come in two flavors or styles there's a vertical axis wind turbine and horizontal axis wind turbine large industrial wind turbines are generally of this style and uh there's basically one concept of design and uh they're fairly well understood by the average person one of the hard things about it is all the heavy and complex machinery is up in the air which then requires a strong support and two of the main considerations for use in a home setting is blade noise and shadow strobe when the sun gets low in the sky the shadow of the blades spinning across your windows is very annoying and whether it's you or your neighbor uh this can be a big problem uh which sometimes is not uh thought about too much ahead of time the another problem is there has to be some system to keep that blade turned facing the wind and that adds to the complexity now when we talk about vertical axis turbines there's many different types and they're basically divided into drag type and lift type and the lift type has blades and the drag type may or may not depending on how it's built lift types are generally more complex than the drag type and they must be started whereas the drag type is self-starting sometimes a drag type is employed within a lift type just to get it started so the lift type also has sunblade noise not as bad as the vertical the horizontal axis because the tips of the blades are not going all that much faster than the wind speed here the tip of the blade can be going up to 10 times the speed of the wind and these can also have shadow strobe because they're generally individual vertical blades uh and a drag type can be built in a way that the shadow doesn't change as it turns now i've included links to a lot more information about both vertical and horizontal axis wind turbines and uh videos showing some examples of these and uh several videos showing scams because there are so many different designs of the vertical axis people don't readily understand them and can't see when something is obviously a scam so i'll look at the videos about scams so you don't get suckered into that there's also some scams on low power horizontal axis wind turbines but generally the situation is not nearly as bad as with the vertical axis because the heavy machinery for genera for a generator and so forth can be located at the bottom of the vertical axis wind turbine a very flimsy support can be used and in fact guy wires can be employed if you make this a bearing so that the vertical support can rotate uh it's possible to use guy wires and uh because these type of windmills are much lighter than those the support can really be quite flimsy let's talk about a drag type vertical axis wind turbine which is also known as a savonius type and for the moment i've simplified things into a an arrangement similar to a drag cup anemometer for measuring wind velocity and here we have two cups on a pivot point and i have a link below to this article on wikipedia called drag coefficient where it shows the drag coefficients for various shapes of things that are in the in an ear path so uh there's a force equation it's called the drag equation where the force on an object is one half of rho which is the density of the fluid times the velocity squared times the coefficient of drag times the area it's a cross-sectional area of the thing that's being blown on so for a cup shape with the wind blowing behind it like this the drag coefficient is 1.42 and when the wind's blowing on the other side the drag coefficient is 0.38 so if we have a an arrangement here where we're not accelerating that means that force a is equal to force b so if we do that we can see that everything drops out except these terms right here and for these coefficients right here we end up with this term equal to 0.517 and if we cross multiply and add and subtract we end up where the velocity of the cup which both ways is 31.8 percent the speed of the wind now i think you can see if there was some way to reduce the drag of this cup to zero that .38 would be zero when you cross multiply this term goes away and we end up with vw minus v equals zero so in that case the velocity of the cup is equal to the velocity of the wind now in either case to extract any torque out of the shaft it's going to slow the cups down because it's going to require more force to produce the torque that you're taking away so but you hit you're going to have more efficiency when you're starting at almost three times the speed but of course that to achieve that there has to be a way to reduce that cup drag to zero in that direction which you can't totally do but we can approximate it and i'll show you how to go about that here shortly now let's think of these cups mounted on a drum and maybe even have more cups with that arrangement it doesn't matter what direction the wind is coming from it's going to catch in these cups here and if we could make these cups go away then we can have that condition there so i've built a little demonstrator that's a proof of concept to show this in action so we'll look at that next well i hope you won't laugh at my setup here but basically we have a fan to make some wind and here this is on a shaft it's free to rotate it's basically a coffee can with strips of paper towel each paper towel is taped to the can here and then the ends are taped here and at the bottom so if the wind were blowing in this direction it would catch in there but if the wind's in the opposite direction it should tend to collapse and therefore reduce the coefficient of drag as wind blows so let's turn on the wind here and as you can see it's self-starting i put the black background there to help show that over here the profile shows the towels somewhat collapse but on this side you can see them bulging out so the bulging out should increase the drag coefficient over here and by collapsing on this side that should reduce the drag now that's a rather low setting of the fan there i think you can see the how flat the profile is over here and it's quite bulged out over there so that indicates we're also getting some cowanda effect where the air is coming around behind the unit and we're also getting some augmentation where the air is hitting this side it's then forced to go around the sides now in a real design i plan to use cloth instead of paper towels and having things attached in a much better way so that will be our next step is to enhance this proof of concept a little better here's our coffee can demonstrator which we showed will turn in the wind so let's move up to something a little bigger about a nice trash can so it's a little more realistic i'm envisioning uh the next step would be to a large 30-gallon type trash can and that might be large enough to actually produce a usable amount of power now here i've taken a trash can and two pizza pans and the plan is to have our uh cloth between the two discs here and we can play around with shapes uh we can make it like a drag cup uh anemometer like our coffee can exam sample and by proper shaping we might actually be able to make it into like a paraffin foil type sale and uh we can experiment and see what kind of shape works best now a small diameter thing like this will turn at a higher speed higher revolutions per minute but a larger container although it'll turn slower it'll produce more torque and power is torque times revolutions per minute so there's trade-offs between speed and torque now something else so we could do is actually go vertically and stack up units uh basically as high as we want we could have another pizza pan on top here so let's uh try out a set of sails this time made of fabric and then we'll go out to the wind tunnel and see what we can learn okay it's time to make our wings or sails or cups whatever we're gonna call these fabric pieces and if we have a round plate and a cylinder then another round plate we want the uh sail to be collapsed totally when it's coming around into the wind so if we draw a cross-section of that we want to anchor our sail here it has to be long enough when it's collapsed to go around there it would be anchored at these points and the other edge of the sail we want to be this length the length between the plates on the end so that means it's basically a trapezoid shape so this edge is going from there to there this edge is going from here to here so let's go cut some material here i laid out uh hopefully uh the blade shapes that i'm gonna try and use the first time that's the trapezoidal shapes and then i painted the lines that i'm going to cut with a clear acrylic paint and hopefully that'll keep the edges from fraying and on a final version probably you would hem all those lines it appears gray because i have a piece of gray plastic underneath this cloth and this cloth is a cotton and polyester mix okay here we are back in our wind tunnel and i have one of the sails mounted it's just held in place with black electrical tape and let's see if it'll turn in the wind i'll turn the fan on low speed and here we see it the seal was collapsed at that point and there it opens so as it comes around from the left it is collapsed and offering minimal wind resistance and then it opens up and catches the wind let's go a little faster so i'll cut out another sail and add it and see how that works okay i've added a second sail and we'll turn the fan on low speed again so well i might as well add the other four sails it looks like it's going to work pretty good okay here we are with all six sails in place so let's turn the fan on to a low speed here i think you can see quite well how they're collapsed as they come around on the left side and then open up when they catch the breeze on the right hand side so let's take the speed up a notch so seems to be working pretty good let's go for broke and put the fan on high speed okay i think the next step is to try and get some idea what the velocity of the air is from this fan that i'm using this uh device is a pedo tube it's used for measuring the velocity of air and right now it's through tubing connected to a differential pressure manometer the first division here is 0.1 inches of water pressure and that corresponds to about 14 miles per hour of air velocity so let's run our fan and see what our air velocity really is i'll set the fan on high speed it's hard to show what i'm doing here but i'm going out to the edge of the airstream and then coming in and i hope you can see the pressure going up and we reach just an air over the uh 0.1 inches of water now as i come into the center of the fan i'm moving towards the camera at the center of the fan i'm showing almost no airflow at all and then as i continue on across the fan it's hard to really show what's going on here but we come back up to our a little over 0.1 inches of watercolor so this is a very poor distribution of airflow from a fan like this next let's try and look at the uh turbulence i have a uh just a piece of string glued on the end of a stick and when it when i'm holding it near the center of the fan it is rotating you can tell that there's really a vortex of airflow as i go away you can see it's pointing down and if we come this way it points up and again that's because the air is rotating this way see how crazy this is it's actually rotating faster than the camera is showing so this is a extremely poor setup for testing our wind turbine but it's all i have right now well we're at the end of this video i plan to keep on working and come up with the best shape possible and the simplest easy to build design as possible and i'll report to you in another video so if you don't want to miss it be sure and subscribe so that you'll be notified when uh my sequel video comes out uh in the meantime uh you know if you got anything out of this video if you click on the thumbs up uh that'll help get this video uh suggested to other viewers so i hope to see you in the next video

Channel: Jim's cool stuff

Views: 44,514

Keywords: vertical axis wind turbine

Id: 2k41_OZBo5k

Length: 29min 43sec (1783 seconds)

Published: Fri Jan 14 2022