X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.3.1) with ESMTP id 4089635 for flyrotary@lancaironline.net; Wed, 20 Jan 2010 15:51:40 -0500 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet2.per.eftel.com (Postfix) with ESMTP id 8EDD51736F2 for ; Thu, 21 Jan 2010 04:50:59 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id 45FE5BEC0CD for ; Thu, 21 Jan 2010 04:44:14 +0800 (WST) Message-ID: <07AD20E645094C0EB462675BA1E7563B@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Wedge/Oblique Duct Date: Thu, 21 Jan 2010 06:44:15 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0041_01CA9A65.2639D860" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 100120-1, 01/20/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0041_01CA9A65.2639D860 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ed, Thanks, I thought we were discussing bell shaped ducts, I must have = confused myself, however that info on wedge shaped and streamlined wedge = shaped ducts is extremely interesting - a picture says a thousand = words. I can see instantly why there is a bump in the design. Although I do like the bell shaped duct and I'm sure it's the best, for = ease of construction, I might look at the streamlined wedge shaped duct. Thanks for that info - it's much appreciated. George ( down under) =20 George, here are two figures from K&W - one could be described as a = "Wedge" figure 12-6 and the other one a "streamline" wedge figure 12-12. =20 Always dangerous for me to try to interpret what K&W are really = saying, but from what I get from these two figures, it would appear that = the "streamline" wedge permits you to use a smaller inlet (Ai =3D 0.30 = Ab) for the same performance (same losses) that you get with a larger = opening Ai =3D 0.44 Ab for the pure Wedge. But, that is just my take on = it. =20 The slight bump (where the 64 deg angle is annotated) of the = Streamline wedge may be to increase the boundary layer velocity to delay = separation of the boundary layer in that far corner where duct meets = core. =20 =20 Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm =20 __________ Information from ESET NOD32 Antivirus, version of virus = signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0041_01CA9A65.2639D860 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Ed,

Thanks, I thought we were discussing = bell shaped=20 ducts, I must have confused myself, however that info on wedge = shaped and=20 streamlined wedge shaped ducts is extremely interesting - a = picture says a=20 thousand words. I can see instantly why there is a bump in the=20 design.

Although I do like the bell shaped duct = and I'm=20 sure it's the best, for ease of construction, I might look at the = streamlined=20 wedge shaped duct.

Thanks for that info - it's much=20 appreciated.

George ( down under)

George, here are two = figures from=20 K&W =96 one could be described as a =93Wedge=94 figure 12-6 and = the other one a=20 =93streamline=94 wedge figure 12-12.

Always dangerous = for me to=20 try to interpret what K&W are really saying, but from what I get = from=20 these two figures, it would appear that the =93streamline=94 wedge = permits you to=20 use a smaller inlet (Ai =3D 0.30 Ab) for the same performance (same = losses) that=20 you get with a larger opening Ai =3D 0.44 Ab for the pure Wedge. = But, that=20 is just my take on it.

The slight bump (where = the 64 deg=20 angle is annotated) of the Streamline wedge may be to increase the = boundary=20 layer velocity to delay separation of the boundary layer in that = far=20 corner where duct meets core.

Ed

Ed=20 Anderson

Rv-6A N494BW Rotary=20 Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

__________=20 Information from ESET NOD32 Antivirus, version of virus signature = database=20 3267 (20080714) __________

The message was checked by ESET = NOD32=20 Antivirus.

http://www.eset.com

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Homepage: http://www.flyrotary.com/
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