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<DIV>Right; I meant to say all other things remaining the same. </DIV>
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<DIV>In a message dated 9/5/2013 5:26:27 P.M. Central Daylight Time,
piolenc@archivale.com writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" color=#000000 size=2 face=Arial><BR>On
9/6/2013 1:34 AM, JimToddPsub@aol.com wrote:<BR>> Hi Marc,<BR>> I think
the premise is that for a /given power input/, a larger diameter<BR>> prop
is going to /result/ in a lower RPM, not that there is an inherent<BR>>
advantage in lower RPM within the scope of the question.<BR><BR>If the pitch
is kept the same, then that's true. Otherwise, up to the <BR>cavitation limit,
speed is an independent variable. And for the reason I <BR>gave it is
advantageous to keep it higher rather than lower. Of course, <BR>at some point
you will encounter diminishing returns, where the power <BR>saved by reducing
swirl is eaten up in additional friction drag.<BR><BR>Calculate, calculate,
calculate...<BR><BR>Best,<BR>Marc<BR>-- <BR>Archivale catalog:
http://www.archivale.com/catalog<BR>Polymath weblog:
http://www.archivale.com/weblog<BR>Translations (ProZ profile):
http://www.proz.com/profile/639380<BR>Translations (BeWords profile):
http://www.bewords.com/Marc-dePiolenc<BR>Ducted fans:
http://massflow.archivale.com/<BR>_______________________________________________<BR>Personal_Submersibles
mailing
list<BR>Personal_Submersibles@psubs.org<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR></FONT></BLOCKQUOTE></DIV></FONT></BODY></HTML>