Fluid Dymanics of Drag – Boundary Layers

Excellent video showing in real experiments you can understand and see. Shows what the boundary layer is, what a stall looks like (if you could see the air) and vorticity. EXCELLENT!

Part 1:

Part 2:

Notice also as the airfoil is inclining to higher and higher angles of attack, that the air is not split on what appears to be the most forward portion of the airflow, but rather below that portion of the airfoil. There is a ton of information here to help you understand why things work the way they do. Enjoy!

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The Fluid Dynamics Of Drag

Excellent video from days of old that demonstrate some very important aerodynamic principles.  The different drag produced by common objects is shown on a scale. You’ll be amazed.

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Man Flys With Self Built Flapping Wings

Ok, all in all I am thinking this is big hoax rivaled only by the Global Warming hoax. However, on alot of levels it is every interesting. If it’s faked, it’s very well done. You can visit his website an do some reading for yourself. Of course he’s not flying right now because he’s taken it appart for some repairs and the weather and yadda yadda yadda. There is also an interesting mention of duck tape. Decide for yourself.

I don’t know if I should call him a Pilot or a Perp, but here is his website: Human Birdwings

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Handy Factors For Common Calculations

Calculating Pitch Speed:
RPM X Pitch Inches x .0009469 = MPH Pitch Speed

Convert wing area from square decimeters (dm) to Square Inches and back:
Sq dm x 15.5 = Square Inches
Square Inch x .064516 = Square dm

Servo Torque:
KG CM x 13.887 = Inch Ounces
Inch Ounces x .072 = KG CM

Ounces & Grams:
Grams X .03527 = Ounces
Ounces X 28.3495 = Grams

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Expanding Your Airfoil Knowledge

Erik Dahl Christensen’s Airfoil History
If like me, you love to design aircraft and want to get a better handle on airfoils, Eric Christensens’s site is an excellent study. Click his home link to find calculators and other sailplane design information. Even if your not into sailplanes, the information is clearly presented and it’s influenced my thinking and understanding of airfoils on many levels. Studying other aircraft disciplines will help with your discipline whatever it is. I found the Airfoils section of this site very interesting. In fact, I may go back and give it a read again soon. I’m saving the link here for that purpose and to share it with you. I am currently working on my first sailplane kit and this site has helped me a great deal. Get some glue on your fingers!

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