X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao102.cox.net ([68.230.241.44] verified) by logan.com (CommuniGate Pro SMTP 5.3c4) with ESMTP id 4034086 for flyrotary@lancaironline.net; Mon, 21 Dec 2009 15:16:37 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.44; envelope-from=alventures@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao102.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20091221201559.JMLM8308.fed1rmmtao102.cox.net@fed1rmimpo03.cox.net> for ; Mon, 21 Dec 2009 15:15:59 -0500 Received: from BigAl ([72.192.128.205]) by fed1rmimpo03.cox.net with bizsmtp id KwFy1d0064S1t5C04wFyxz; Mon, 21 Dec 2009 15:15:58 -0500 X-VR-Score: 0.00 X-Authority-Analysis: v=1.1 cv=hxRkenI+XOLoHPjz51PhBd6+pm8nOe1puOOeXS7yE/Y= c=1 sm=1 a=Vegc0WxVmH5BHtpNDyThtA==:17 a=LZIHdCgdUeUth-J32kkA:9 a=EolK3FHNEQxYb-5Rs5vvVRqPT4MA:4 a=Y2VNeNrzAAAA:8 a=yMhMjlubAAAA:8 a=TW66zc2HAAAA:8 a=SSmOFEACAAAA:8 a=HQ31llbKAAAA:8 a=s2CwvL1dJFL_ryKLFTcA:9 a=axEBJAkR4LsOkxj8v6kA:7 a=NuuITlLkcMN0gLtMoGMY0AOTdaIA:4 a=Vegc0WxVmH5BHtpNDyThtA==:117 X-CM-Score: 0.00 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Air Flow Question Date: Mon, 21 Dec 2009 12:16:36 -0800 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0029_01CA8237.71443CB0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6856 Importance: Normal Thread-Index: AcqCcGz91TXxzg9tRkqZXT7LKFLz1gACX7yQ X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0029_01CA8237.71443CB0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Thomas; Yes. For our speeds and pressures the air can be treated as essentially incompressible. So expanding the flow area by factor of 4 will reduce = the average flow velocity by factor of 4. What the flow profile will be = depends on your duct design. =20 Al G =20 Subject: [FlyRotary] Air Flow Question =20 If I have a volume of air entering my scoop at 180 kts and expand the = volume of the chamber by 400% can I expect the speed of the airflow to drop to = 45 kts at that point? T Mann =20 ------=_NextPart_000_0029_01CA8237.71443CB0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Thomas;

Yes. For our speeds and pressures = the air can be treated as essentially incompressible.  So expanding the = flow area by factor of 4 will reduce the average flow velocity by = factor of 4.  What the flow profile will be depends on your duct = design.

 

Al G

 

Subject: [FlyRotary] Air Flow Question

 

If I have a volume of air entering my scoop at 180 kts and expand the = volume of the chamber by 400% can I expect the speed of the airflow to drop to 45 = kts at that point?

T Mann

 

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