X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ispmxmta05-srv.windstream.net ([166.102.165.166] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2189397 for flyrotary@lancaironline.net; Fri, 20 Jul 2007 10:31:47 -0400 Received-SPF: pass receiver=logan.com; client-ip=166.102.165.166; envelope-from=montyr2157@alltel.net Received: from ispmxaamta05-gx.windstream.net ([216.96.20.30]) by ispmxmta05-srv.windstream.net with ESMTP id <20070720143107.CCDG7621.ispmxmta05-srv.windstream.net@ispmxaamta05-gx.windstream.net> for ; Fri, 20 Jul 2007 09:31:07 -0500 Received: from Thorstwin ([216.96.20.30]) by ispmxaamta05-gx.windstream.net with SMTP id <20070720143107.PVUD5606.ispmxaamta05-gx.windstream.net@Thorstwin> for ; Fri, 20 Jul 2007 09:31:07 -0500 Message-ID: <004501c7cada$a1905320$6501a8c0@Thorstwin> From: "M Roberts" To: "Rotary motors in aircraft" Subject: Oil cooler inlet Date: Fri, 20 Jul 2007 09:31:16 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0042_01C7CAB0.B898E070" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_0042_01C7CAB0.B898E070 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Al, I think you are on the right track. The first set of VG's were probably = still in the boundary layer. They won't work unless you are entraining = high energy air into the BL. You could probably tell by using the soap = or dirty oil trick to see how effective they are at mixing the air ahead = of the inlet.=20 Other than a diverter, or a bleed of some type, I can't come up with any = clever soloutions to solve the boundary layer injestion. If you want to just live with the boundary layer injestion and have a = purely internal soloution: You could try a mixing vane. It would be just like Ernest's vane except = with large ripples in it. Think of the lobed exhaust mixers on a jet = engine. The idea is to have alternating jets of high and low energy air. = This could help homogenize the flow and with TJ's re-contour stop the = seperation problem. Monty Monty; you may well be right; it may take a combination. However, I did = put VGs in front of the entrance, and it did not make a noticeable = difference. They were only about 8" forward of the entrance because of = the gear well that is there. I think I will try again with them further = forward - on the gear door covers; and make them a bit taller this time. = =20 Al ------=_NextPart_000_0042_01C7CAB0.B898E070 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Al,

I think you are=20 on the right track. The first set of VG's were probably still in the = boundary=20 layer. They won't work unless you are entraining high energy air into = the BL.=20 You could probably tell by using the soap or dirty oil trick to see = how=20 effective they are at mixing the air ahead of the inlet. =

Other than a=20 diverter, or a bleed of some type, I can't come up with any clever = soloutions to=20 solve the boundary layer injestion.

If you want to=20 just live with the boundary layer injestion and have a purely internal=20 soloution:

You could try a=20 mixing vane. It would be just like Ernest's vane except with large = ripples in=20 it. Think of the lobed exhaust mixers on a jet engine. The idea is to=20 have alternating jets of high and low energy air. This could help=20 homogenize the flow and with TJ's re-contour stop the seperation=20 problem.

Monty

 

Monty; you may=20 well be right; it may take a combination. However, I did put VGs in = front of the=20 entrance, and it did not make a noticeable difference.  They were = only=20 about 8=94 forward of the entrance because of the gear well that is = there.  I=20 think I will try again with them further forward =96 on the gear door = covers; and=20 make them a bit taller this time. 

 

Al

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