Mailing List flyrotary@lancaironline.net Message #33662
From: Perry Mick <pjmick@verizon.net>
Subject: ducted fans
Date: Mon, 18 Sep 2006 17:56:53 -0700 (PDT)
To: <flyrotary@lancaironline.net>
Go for it Rusty!
 
I would like to build a LSA canard using a direct-drive rotary much like I had in the Long-EZ. LSA speed limit is 120 knots, I was doing 135.
http://www.bridgingworlds.com/LSA.htm  There are some aspects of the ducted fan that I miss (safety and simplicity).
 
Even though I have the domain http://www.ductedfan.com I admit my installation was not a ducted fan, but a shrouded propellor. With the relatively low HP of our engines as compared to turbines, it will be difficult to get a "high solidity" fan to work (lots of blades that look "solid" or no air gaps when you look at the face of the fan). You will not have enough HP to turn it up. One definition of the difference between "shrouded propellor" and "ducted fan", is the ducted fan has a duct longer than the fan diameter. My shroud was only 24" long while the fan was 38" in diameter. For your gyro application, I would think it would still be a shrouded propellor, as I doubt you have room for a long duct.
 
Perry
 
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Thanks for the additional replies.  I think I've collected enough info already to look further into trying this, but it will be a couple months before that could happen, so hold all those thoughts for now.  In the mean time, I've got some reading to do on Perry's site, if for no other reason but to get up to speed on terminology.  Richard lost me with "blade solidity" :-)
 
FWIW, I did order my Harbor Freight mobile test stand today, and will be bringing all the rotary engine stuff home as soon as I take the RV-8 to the hanger for final assembly (less than a month from now). 
 
Cheers,
Rusty (cool domain coming soon)
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