Return-Path: <13brv3@bellsouth.net> Received: from imf16aec.mail.bellsouth.net ([205.152.59.64] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2911051 for flyrotary@lancaironline.net; Tue, 30 Dec 2003 14:10:54 -0500 Received: from rad ([68.155.98.142]) by imf16aec.mail.bellsouth.net (InterMail vM.5.01.06.05 201-253-122-130-105-20030824) with ESMTP id <20031230191046.PSFZ1884.imf16aec.mail.bellsouth.net@rad> for ; Tue, 30 Dec 2003 14:10:46 -0500 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: aluminum hose bungs/fittings, evap core mounting Date: Tue, 30 Dec 2003 13:10:48 -0600 Message-ID: <007601c3cf08$a28ec760$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0077_01C3CED6.57F45760" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0077_01C3CED6.57F45760 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable [Maybe it will just be for a second while you go through this or that = RPM. Or (with my luck) it will be for hours on end while you try to make it to Sun&Fun. The amount of movement induced into the cooler may be nearly undetectable. Just holding on lightly and revving the engine may show it off. Maybe = not. Some airplane engines cannot use some props because of this.] =20 Hi again Lynn, =20 Thanks, as always for the comments. I hope you're not getting carpel = tunnel from all this typing :-) I understand the principal of harmonics, and agree that there are no end to the variables that determine the = offending frequency. For example, say you construct a perfect isolation from the engine, then the airflow through the core shakes it at a critical = frequency (which would be my luck btw). I just don't think there's any way to = know what will happen without testing it. =20 =20 I'm going to keep thinking about this, and would still like to see pics = of other peoples evap mounts (thanks also to Jim and his funny firewall). = I can think of a couple ways to add some isolation to the cores, without changing their location, so I can proceed with the current hard mounts, = at least through ground testing. I'd like to see if I can get any = indication of whether they will have a problem before I change it all. =20 =20 Thanks again, Rusty (stubborn, slow learner) ------=_NextPart_000_0077_01C3CED6.57F45760 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message

[Maybe it will just be for a second while you go = through this or=20 that RPM. Or
(with my luck) it will be for hours on end while you try = to make=20 it to
Sun&Fun. The amount of movement induced into the cooler may = be=20 nearly undetectable.
Just holding on lightly and revving the engine = may show=20 it off. Maybe not. Some
airplane engines cannot use some props = because of=20 this.]

 
Hi again = Lynn,
 
Thanks, = as always for=20 the comments.  I hope you're not getting carpel tunnel from all = this typing=20 :-)   I understand the principal of harmonics, and agree that = there=20 are no end to the variables that determine the offending = frequency.  For=20 example, say you construct a perfect isolation from the engine, = then the=20 airflow through the core shakes it at a critical frequency (which = would be=20 my luck btw).  I just don't think there's any way to know what will = happen without testing it.  
 
I'm = going to keep=20 thinking about this, and would still like to see pics of = other peoples evap=20 mounts (thanks also to Jim and his funny = firewall).  I can=20 think of a couple ways to add some isolation to the cores, without = changing=20 their location, so I can proceed with the current hard mounts, at least = through=20 ground testing.  I'd like to see if I can get any indication = of=20 whether they will have a problem before I change it all. =20
 
Thanks=20 again,
Rusty = (stubborn, slow=20 learner)


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