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<DIV>So which one is more noisy?</DIV>
<DIV> </DIV>
<DIV>VB</DIV>
<DIV> </DIV>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">-------------- Original message -------------- <BR>From: "Fred Huber" <fhhuber@clearwire.net> <BR>
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<DIV><FONT size=2>prop noise.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>You can hear the difference in an APC prop if you sand the TE to get rid of the knife edge. They are using the sharp TE and thin airfoil.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Easy to confirm: Get a wattmeter and an electric drive. Turn the APC prop appropriate for the motor and do a sound check... then sand the TE (such as is commonly done by some people...) check sound and power demanded by the motor again.</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=bob@toprudder.com href="mailto:bob@toprudder.com">Bob Richards</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=nsrca-discussion@lists.nsrca.org href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, February 13, 2007 10:29 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Trailing Edge</DIV>
<DIV><BR></DIV>
<DIV>Ok, why don't we chop off the trailing edge of our props?</DIV>
<DIV> </DIV>
<DIV>Bob R.</DIV>
<DIV><BR><BR><B><I>Nat Penton <<A href="mailto:natpenton@centurytel.net">natpenton@centurytel.net</A>></I></B> wrote:</DIV>
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<DIV><FONT face=Arial size=2>Dean</FONT></DIV>
<DIV><FONT face=Arial size=2>The old NACA must have done this research in the distant past. I recall, in the 80s, Jim Bede extolling on the virtues. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> The Princeton project, that would be fun, especially as a student. Would have kept my attention <G>. Nat</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=d.pappas@kodeos.com href="mailto:d.pappas@kodeos.com">Dean Pappas</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=nsrca-discussion@lists.nsrca.org href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, February 13, 2007 10:03 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Trailing Edge</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff size=2>Thanks Nat,</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff size=2>I have a guy in the local club who corroborates Barnaby's statement. Locally to NSRCA D1, back in the 80's he was known as "forever in Sportsman George".</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff size=2>He is recently retired from teaching at the Aero group at Princeton U. and he still coaches the students involved in the weight lifting contest.</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff size=2>It was nice to have an excuse to go hunt him down!</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff size=2>later,</FONT></SPAN></DIV>
<DIV><SPAN class=725475815-13022007><FONT face=Arial color=#0000ff size=2>Dean</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT face="Times New Roman">Kodeos Communications</FONT> <BR><FONT face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT face="Times New Roman">South Plainfield, N.J. 07080</FONT> <BR><FONT face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT face="Times New Roman">d.pappas@kodeos.com</FONT> </DIV>
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<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma size=2>-----Original Message-----<BR><B>From:</B> nsrca-discussion-bounces@lists.nsrca.org [mailto:nsrca-discussion-bounces@lists.nsrca.org]<B>On Behalf Of </B>Nat Penton<BR><B>Sent:</B> Tuesday, February 13, 2007 1:05 AM<BR><B>To:</B> NSRCA Mailing List<BR><B>Subject:</B> [NSRCA-discussion] Trailing Edge<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>Kitplanes, Dec 06 Wind Tunnel by Barnaby Wainfan</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>" The airfoil with the chopped trailing edge will produce slightly more lift at the same angle of attack than a sharp trailing-edged airfoil. Because the wake is filled in the controll is crisper and more effective and does not have to move as far to cause a change in lift"</FONT></DIV></BLOCKQUOTE>
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