Posted By:
Please see very nice article in CAFE blog. http://blog.cafefoundation.org/




Last year my presentation did not draw a big crowd, but I hope those that came enjoyed it and learned a bit. I picked up some helpful ideas from the audience. This year expands on last year's presentation and concentrates on three areas:
1. Using the "triangle tool" to match your airplane to your new prop. Get it right before you carve or buy.
2. Using the "triangle tool" to understand (and truth-test) and even predict how some Green Flight Challenge entrants will do.

3. Looking at how we estimate BHP for a given speed and altitude. The better we do this, the better we can match that prop.
The tool is a big improvement in user-friendliness from the prior spreadsheet. The tool, in its present form, can be found on this web page: http://home.cogeco.ca/~n17hh/Models/models.html It is the first bullet in the left hand box. Last year's presentation is at the top of the page. I hope to do live demo's of some airplanes, using the tool.
7/29/2011 - 10:00 AM - 11:15 AM - Homebuilders Hangar Aircraft Spruce & Specialty - Map
Power, Drag, Speed and Propeller Design - Last year's talk was about how to find your airplane's drag curve. This year's will review, then provide tools to estimate power and match the prop to the airplane. You design your new prop to produce a specified net power or to overcome specified drag. That will be at a specified diameter, blade count, density altitude, TAS and RPM. But how do you know the BHP? How can you predict the TAS?
I will post the PowerPoint presentation ahead of time (same page), but I'm still polishing it at this time.
I hope to see you there.