X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao105.cox.net ([68.230.241.41] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2190559 for flyrotary@lancaironline.net; Sat, 21 Jul 2007 00:22:58 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.41; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao105.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20070721042218.WKNF1399.fed1rmmtao105.cox.net@fed1rmimpo02.cox.net> for ; Sat, 21 Jul 2007 00:22:18 -0400 Received: from BigAl ([72.192.132.90]) by fed1rmimpo02.cox.net with bizsmtp id S4NJ1X0051xAn3c0000000; Sat, 21 Jul 2007 00:22:18 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Oil cooler inlet Date: Fri, 20 Jul 2007 21:23:58 -0800 Message-ID: <000001c7cb57$56e91e60$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C7CB14.48C5DE60" 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 V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C7CB14.48C5DE60 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Whatever the gear well covers do I don't know. I have 9.5" steady H2O = ram pressure in front of the middle of the scoop, 5/8" below the underwing surface; and that's plenty adequate. =20 Al =20 Subject: [FlyRotary] Oil cooler inlet =20 Al, =20 I'm in agreement with TJ on this one. Tuft test is definitely in order. = I did not realize that the gear door and wheel fairing were where they = are. Even if the transition is fairly smooth, the opening at the wheel and = the gaps in the door are going to make a mess in the area aft of the door. = Think little jets of air from all the gaps. This will trip the boundary layer = and make it much thicker than normal. It would have to be fully sealed (air tight) around the gear door to stop this. =20 Any high pressure that the open wheel well develops will squirt out = around the door.=20 =20 I would test to see how bad the flow is loused up around the gear door = with some oil or tufts. You may find that sealing the fairing up improves = things a lot. =20 Sealing the gap around the cooler certainly can't hurt things. =20 Interested to see how the VG's and gap seal improve things. =20 Armchair QB in action here ;-) =20 Monty ------=_NextPart_000_0001_01C7CB14.48C5DE60 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Whatever the gear well covers do I don’t = know. I have 9.5” steady H2O ram pressure in front of the middle of the = scoop, 5/8” below the underwing surface; and that’s plenty = adequate.

Al

Subject: [FlyRotary] Oil cooler inlet

Al,

I'm in agreement with TJ on = this one. Tuft test is definitely in order. I did not realize that the gear = door and wheel fairing were where they are. Even if the transition is fairly = smooth, the opening at the wheel and the gaps in the door are going to make a mess = in the area aft of the door. Think little jets of air from all the gaps. This = will trip the boundary layer and make it much thicker than normal. It = would have to be fully sealed (air tight) around the gear door to stop = this.

Any high pressure that the = open wheel well develops will squirt out around the door.

I would test to see how bad = the flow is loused up around the gear door with some oil or tufts. You may find = that sealing the fairing up improves things a = lot.

Sealing the gap around the = cooler certainly can't hurt things.

Interested to see how the = VG's and gap seal improve things.

Armchair QB in action here = ;-)

Monty

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