X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: <13brv3@bellsouth.net> Received: from imf25aec.mail.bellsouth.net ([205.152.59.73] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 949173 for flyrotary@lancaironline.net; Wed, 18 May 2005 16:05:04 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.73; envelope-from=13brv3@bellsouth.net Received: from ibm69aec.bellsouth.net ([65.6.194.9]) by imf25aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20050518200416.PISI2545.imf25aec.mail.bellsouth.net@ibm69aec.bellsouth.net> for ; Wed, 18 May 2005 16:04:16 -0400 Received: from rd ([65.6.194.9]) by ibm69aec.bellsouth.net (InterMail vG.1.02.00.01 201-2136-104-101-20040929) with ESMTP id <20050518200415.XKJQ9550.ibm69aec.bellsouth.net@rd> for ; Wed, 18 May 2005 16:04:15 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: More MAP measurement questions Date: Wed, 18 May 2005 15:04:27 -0500 Message-ID: <004401c55be4$cb944490$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0045_01C55BBA.E2BE3C90" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 This is a multi-part message in MIME format. ------=_NextPart_000_0045_01C55BBA.E2BE3C90 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Yes , I measure in the runner and do not have a plenum down stream of the T/B. But Tracy and I have had this very discussion, my MAP attempts to measure the stagnation or total pressure. My comment to Tracy is that if he has a plenum after the T/B , that he is measuring the stagnation pressure. My tube sticking into the runner has a 45 degree slant cut on it and the opening faces toward the average flow. Tracy says that the runner sees all kinds of pressures as the rotor inlet opens and closes. I agree with that, but think you want the average stagnation pressure which is what his plenum measures. I added a lawnmower fuel filter in the MAP line to attempt to dampen any pulses out. Hi Bernie, Thanks for the comments. What are the inside diameters of your tubes (assuming primary and secondary are different)? Also, what RPM are you seeing static, when you said you measured essentially 30"? Do you think you could be getting any ram-air effect in your MAP port with the open end pointing somewhat into the air stream? Thanks, Rusty (more questions, since you're not flying) ------=_NextPart_000_0045_01C55BBA.E2BE3C90 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
Yes , I measure = in the=20 runner and do not have a plenum down stream of the T/B. But Tracy and I = have had=20 this very discussion, my MAP attempts to measure the stagnation or total = pressure. My comment to Tracy is that if he has a plenum after the T/B , = that he=20 is measuring the stagnation pressure. My tube sticking into the runner = has a 45=20 degree slant cut on it and the opening faces toward the average flow. = Tracy says=20 that the runner sees all kinds of pressures as the rotor inlet opens and = closes.=20 I agree with that, but think you want the average stagnation pressure = which is=20 what his plenum measures. I added a lawnmower fuel filter in the MAP = line to=20 attempt to dampen any pulses out.
 
 
Hi Bernie,
 
Thanks for the comments.  What are the = inside=20 diameters of your tubes (assuming primary and secondary are = different)? =20 Also, what RPM are you seeing static, when you said you measured = essentially=20 30"?   Do you think you could be getting any ram-air effect in = your=20 MAP port with the open end pointing somewhat into the air=20 stream?  
 
Thanks,
Rusty (more questions, since you're not=20 flying) 
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