Let's Build an Optimization Tool for DIY Wind Power Airfoils

While I absolutely love the DIY accessibility of home wind power generation projects like the Chispito Wind Power Generator, The DIY aviation nut in me is screaming that we could all get significantly more power out of rigs like this if we had an optimization tool that would ask us our motor specs and what the wind is like where we're mounting our generators, then spit out .stl files of the right shape airfoils to get the most power out of the wind. I don't know what percent difference the average builder could expect to see from optimized blades...but based on the research paper linked at the very bottom of this post, I think it would have to be huge. The difference between an aircraft-optimized airfoil and a wind turbine optimized airfoil can be as much as 50% in normal wind conditions, and neither of those airfoils seem to have much in common with the simple   blades we DIY types make out of cut up PVC pipe.

CNC hot wire foam cutting technology is a good start for rapid prototyping custom airfoils based on .stl files. With this technology in play, I could see the production of custom wind generator blades becomming a great little microfactory business.

The past couple times I started to post something along the lines of "Dear Santa or Jesus or open source community members, next I would pretty please like the following open source tool to exist" I found what I wanted in a Google search. The most recent two examples were free, open source computational fluid dynamics code and an inexpensive, open source stereolithography machine.

This time, the closest I have found to an airfoil optimization tool for DIY wind power generation are these research papers:

• Aerodynamic Shape Optimization of Vertical Axis Wind Turbine Using Differential Evolution: Summarizes the preliminary results of a UT Arlington Aerospace Engineering group's efforts to create an automated airfoil optimization code. Bonus: if you want to learn the basics of wind power theory, read the introduction to this paper. It'll be a great vocab lesson even if math isn't your thing. The group published this paper under the creative commons attribution license...cross your fingers that they will be just as generous with the source code they're working so hard to create.
• Study of the Performance and Robustness of NREL and NACA Blade for Wind Turbine Applications: This study predicts that major power gains (~10-50% over the wind speed range of 3-9mph) would result from building small home-use wind turbines using the airfoils designed for horizontal axis wind turbines by the National Renewable Energy Lab (NREL) as opposed to the currently common practice of using airfoils NASA designed for aircraft back when the agency was still called NACA. As you can see in table 1 and in figure 3 (click here, scroll down), the NREL and NACA airfoils look almost identical. I suspect that using either type would yield a vast improvement over the current DIY standard of cut up PVC pipe.

The top one looks like a great start...but I'd like to see the open source community run with it and start making better wind turbines.

B9Creator: An Open Source Stereolithography Solution for < 3% of the Price

The B9Creator is an open hardware project brought to us by Michael Joyce.

This Wikipedia article claims that stereolithography machines typically cost in the range of $100,000 to $500,000, and use resin that costs between $80 to $210 per liter. The B9Creator delivers this functionality (rapid prototyping using light to solidify resin) for <3% of the price, conservatively, using resin that costs about ten cents a gram. For $2,375, backers on Kickstarter can get a complete kit that can theoretically be assembled in an afternoon. For $3,375, backers get a fully assembled and calibrated machine.

As you can see in the video below, Michael Joyce, the B9Creator's inventor, is committed to the development of open source software and hardware, and is looking forward to the innovations that will be inspired by his creation.

The B9Creator is offers unusually high resolution for a low cost 3D printer (0.05 - 0.1 mm for the B9 vs. 0.2-0.3 for the Makerbot Replicator). The B9Creator starts by slicing a 3D object data file into a stack of 2D images, and projecting the first 2D image onto a thin layer of photo-initiated polymer resin long enough to cure a .05 - 0.1mm layer, which attaches to the build platform behind it. The B9Creator then moves the build platform to break the bond between the cured resin and the projector window, re-positions the build platform above the projector, and projects the next 2D image. The B9Creator repeats this process until the 2D images have been stacked up to produce the finished 3D object.

The B9Creator can build 3D objects at 12-20 mm/hr independent of the object's density. RepRap project and Makerbot 3D printers use fused deposition methods, wherein plastic is melted, extruded through a small nozzle, and 3D objects are built by fusing melted plastic from the nozzle onto the layer below. Because this method (called Fused Deposition Modeling, FDM) relies on the relatively fixed rate at which plastic is melted and extruded through the nozzle, denser objects take significantly longer to build using FDM than more fluffy ones. The build speed of the B-9 creator is dependent on the layer thickness set by the user, but does not depend on the density of each layer.

This video is from the B9Creator's kickstarter pitch, which as of this writing has more than quadrupled its funding goal and still has over a week to go:





Also via the kickstarter pitch, here is a video showing the B9Creator prototype in action, printing the Metatron:




Have you seen the B9Creator in action?

Tell me about it in the comments! I am especially curious how sturdy the resin objects produced by the B9Creator are, and what, if any, surface prep is required to clean the models of any un-cured resin film.

About the Open Source Tech Revolution

Purpose

The purpose of the Open Source Tech Revolution is to make freedom and autonomy more accessible to those who want it.

The purpose of the Open Source Tech Revolution Blog is to help get the OSTR rolling!

Lots of us have great ideas for new technology and new products that have a lot of potential to improve lives or make money.  Often, we lack the time, expertise, or skill set to make many of these ideas a reality.  I am a proponent of the idea that just about anyone can learn just about anything, given some time and access to the right information.  Thanks to brick and mortar libraries and great sites like Wikipedia and YouTube, we have a lot freer access to a lot more information than ever before.  Simply having the time to learn what we need to know in order to proceed, and in many cases having the money for the proper tools, equipment and raw materials are still major road blocks to achieving the innovations we envision.  Through networking, and collaborative design efforts, we can bypass those road blocks to an unprecedented extent.

Why would People give good ideas away for free?

We want awesome stuff to exist.  Sometimes people have awesome ideas that they have neither the time nor the expertise to bring to fruition alone. One way to increase your chances of actually using something awesome that you dream up but don't plan to create is to make the idea public and let others attempt to create it.

Philanthropy: Giving away empowering knowledge and technology is a way to give people who need it a chance to improve their quality of life.

Lots of us have ideas we're not using anyway: Given the choice between sharing our good ideas, holding onto them in hopes of future for-profit development, or waiting for others to independently come up with and act on the same idea, some people may benefit most from sharing.

Why would anyone want to work on open-source design projects for free?

• Doing things that really matter makes people happy.
• Being productive makes people happy.
• Taking on challenges makes people happy.
• If you want something to exist, and it doesn't exist yet, you can fix your problem by helping to create it.
• By collaborating on ground-breaking engineering projects, you will probably get to know fascinating people with whom you share exciting interests.
• If you want to learn some useful skills, collaborating on a project where those skills are needed is likely to provide you with added motivation, priceless practice with your new skills, and a network of mentors who already possess the skills you are looking to acquire.
• If you are looking for a career in engineering, science or technology, gaining the experience of collaborating on successful, useful and innovative designs will show prospective employers that you have what it takes.
• If your skills and creativity are underutilized in your current career, collaborating with cutting edge projects as a hobbyist could be a thrilling opportunity to be yourself.
• If you think you might have engineering chops but you are not certain, collaborating on an engineering project would be a useful way to test the waters.

How is posting a bunch of ideas on the internet going to help anyone in any way?


It's probably not going to.  I am researching the efforts of others to crowd-source the development of technical projects and working to develop a web-based collaborative design application that solves as many as possible of the logistical problems with collaborating from a distance.