Showing posts with label engineering. Show all posts
Showing posts with label engineering. Show all posts

Friday, June 15, 2012

Project Falcon: Free Interactive Wind Tunnel Simulation Software

Project Falcon is wind tunnel simulation software brought to us as a free technology preview by Autodesk Labs. The goal of Project Falcon is to help designers intelligently consider the aerodynamic properties of their designs without first having to learn computational fluid dynamics (CFD). This could be a great thing for vehicle designers.

Windows is the only supported operating system, but the minimum hardware requirements look pretty achievable.

To me, the exciting features of Project Falcon are:
  • Free to download; no Autodesk license required
  • Broadly accessible user-interface (Probably less intimidating than Elmer for your first foray into Aerodynamic design)
  • Easy installation (register with Autodesk, download the project falcon installer, run the installer, double click the icon, then open the STL file you want to check the aerodynamics for)
  • Blog/forum support via Autodesk Labs
  • Users develop an intuitive grasp of aerodynamic principals using Project Falcon's rapid visual feedback in response to design and parameter changes
  • No specialized knowledge required to study the aerodynamic properties of your 3D designs
If anything could motivate me to mess around with Microsoft Windows, it's probably Project Falcon, owing to the 2nd and last bullets on the list.

Here is a brief video introduction to Project Falcon via Autodesk Labs.



One thing the Project Falcon overview page emphasizes is the high speed with which this software calculates and displays results. A prominent complaint in the wind power optimization research papers I've run across is that CFD is computationally expensive and time consuming. So is Project Falcon sacrificing quality for speed? Probably. But this Project Falcon Validation paper shows that Project Falcon at least calculated the the correct coefficients of drag for a sphere, a cube, a cone, and an odd polyhedron that looks like a brick with 3 corners cut off and something small sticking out the bottom. I can't help wondering if Project Falcon has potential as a tool for optimizing the shapes of home-use wind turbine airfoils.

In the Aero Challenge, Local Motors has invited members of its open source vehicle design community to to use Project Falcon to help create a more aerodynamic design for the next Peterbuilt big rig.

Monday, June 11, 2012

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.

Monday, May 28, 2012

Open Source Aircraft Design Software from NASA

I hereby retract any complaints I may have recently made about paying taxes.

The heroes at NASA just gave us some open source aircraft design software called Open VSP (vehicle sketch pad). This open source software is designed to let the  user rapidly create high-fidelity parametric design/structural layout for conceptual aircraft designs, resulting in models that can be processed into formats suitable for engineering analysis. According to the wiki, it's been under development since the early 90's, and J. R. Gloudemans, P.C. Davis, and P.A. Gelhausen presented a publication on the development of VSP at the 34th Aerospace Sciences Meeting and Exhibit in January 1996.

I'm guessing VSP has come a long way since then.

This ten-minute video introduces some of the features of Open VSP, by building and analysing an SR-71 Blackbird-like model:



The above video was created by Bill Fredericks, and stolen from the Open VSP Video Tutorial Page, which also contains a handful of more in-depth video tutorial videos created by Ami Patel.

The Open VSP code repository is on GitHub. The Open VSP wiki is here, and the Open VSP google group is here.

If you want to get going with some open source aircraft design, click here to visit the Open VSP project website and download the software.

You can find lots of free resources for open source aircraft design on my aircraft design page.

Tuesday, April 24, 2012

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.