Vertical Wind Turbine - Parametric

thingiverse

3/01/19 update: Now with demonstration video: https://youtu.be/vZWP3Q073KA I tried to capture the RPMs with a tachometer, but it was too bright outside and (duh!) no wind inside. This is a parametric VAWT, or "vertical-axis wind turbine" design. It can produce straight or helical (Gorlov) turbines of any NACA4 foil profile you like. Because lift-type VAWTs have trouble starting from standstill, you may include the drag-type (Savonius) turbine scoops shown above. Also, it seems VAWTs are greatly affected by foil smoothness-- be sure to sand them down. _As for the bracket to mount the turbine:_ You can choose 4 arms (more stable) or 3 arms (less airflow obstruction). Print as many bracket arms as you want, and print the corresponding upper and lower disks. Connect the arms to the upper and lower disks with 20mm M3 screws and locking nuts. There are additional vertical holes to attach a generator assembly above or below the turbine assembly. The included .stl files are designed to accept 4 ball bearings of 608 type to the upper and lower disks, through which a 5/16th inch rod fits nicely. From ground to sky, the order of parts is this: - 608 bearing - bracket disk lower - 608 bearing - nut, tightened against the bottom segment of the turbine - bottom segment of the turbine - nut, slotted into the bottom segment of the turbine - nut, tightened against the previous nut - open rod - nut, tightened against the next nut - nut, slotted into the top segment of the turbine - top segment of turbine - nut, tightened against the top segment of the turbine - 608 bearing - bracket disk lower - 608 bearing - 2 nuts tightened against each other, resting gently on the top 608 bearing. You can download and print the .stl files here, or generate your own VAWT with the included OpenSCAD file. Just by changing a constant in the file, you can change the number of blades, their shape, height, rotation, angle of attack, etc. OpenSCAD looks daunting, but it's simple to use. Inspired by https://www.thingiverse.com/thing:16504, but created from scratch without viewing his code. There's a lot of stuff on the web about various parameters to optimize a VAWT, such as NACA profile, number of foils, angle of foils, height, etc. The files here use NACA2018 based on a number of papers I read, but I'm sure other profiles have merit. If this topic interests you, you may enjoy: 1) Analysis of Different Blade Architectures on small VAWT Performance, L. Battisti, A. Brighenti, E. Benini, M. Raciti Castelli, Journal of Physics: Conference Series 753 (2016) 062009 2) http://www.amics21.com/laveritat/savonius_generator_english.pdf