X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imo-m20.mx.aol.com ([64.12.137.1] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 1029200 for flyrotary@lancaironline.net; Fri, 10 Mar 2006 01:26:26 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.1; envelope-from=WRJJRS@aol.com Received: from WRJJRS@aol.com by imo-m20.mx.aol.com (mail_out_v38_r7.3.) id q.d2.3969ea64 (4539) for ; Fri, 10 Mar 2006 01:25:36 -0500 (EST) From: WRJJRS@aol.com Message-ID: Date: Fri, 10 Mar 2006 01:25:36 EST Subject: Re: [FlyRotary] Re: NACA's, Cooling and Sport Aviation Mag.. To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1141971936" X-Mailer: 9.0 SE for Windows sub 5022 X-Spam-Flag: NO -------------------------------1141971936 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Group, The problem with submerged inlets, and Buly is correct to mention that means flush with the surface, is that they do not handle back pressure well. Ed A posted the original NACA data and their conclusion was that submerged inlets don't work well with RADIATORS. The comments PL has been making are only to re-publish the data. If you do a smoke tunnel test on submerged inlets you will find that once enough pressure is built up they will "flip" and hardly take in any air at all. The actual NACA ducts also have the carefully designed lips, or rounded edges to train the boundry layer into the inlet. The full profile defined by the NACA is rarely used. Most of the inlets we see are some attempt at looking like a NACA inlet, without the trouble of actually BEING a NACA inlet. We used to call this "eyeball engineering." Aircooled engines do work better with NACA inlets as there is less pressure differential than with a radiator. This doesn't mean they will never work, just that the NACA didn't recomend their use with a radiator/heat exchanger. Bill Jepson In a message dated 3/9/2006 8:24:30 PM Pacific Standard Time, atlasyts@bellsouth.net writes: John, would you stop calling it a NACA scoop. Remove the big raised lip and make it flat. Than come and report to us. Your inlet is half submerged and half raised scoop. NACA is a flush with the surface SUBMERGED inlet. Buly On Mar 9, 2006, at 10:44 PM, John Slade wrote: > Dave, > My only cooling intake is the plans Cozy IV NACA. > Cooling has never been a problem. > Regards, > John > > David Staten wrote: >> At the risk of invoking PL's name, anyone else read this months >> Sport Aviation mag from EAA, and notice an article on cooling that >> seems to indicate that NACA's are acceptable and adequate for >> aircraft cooling needs? I have no idea regarding the authors >> credentials, and I no longer monitor PL's "newsletter".. I was >> curious more than anything else... Pauls reaction, others >> reactions, etc. >> >> Translation.. yes.. I'm stirring the pot/Trolling... I figure if >> we are using NACA's on the Velocity, that makes us somewhat of a >> NACA supporter.. >> >> Dave -------------------------------1141971936 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Group,

The problem with submerged inlets, and Buly is correct to mention that=20 means flush with the surface, is that they do not handle back pressure well.= Ed=20 A posted the original NACA data and their conclusion was that submerged inle= ts=20 don't work well with RADIATORS. The comments PL has been making are only to=20 re-publish the data. If you do a smoke tunnel test on submerged inlets you w= ill=20 find that once enough pressure is built up they will "flip" and hardly take=20= in=20 any air at all. The actual NACA ducts also have the carefully designed lips,= or=20 rounded edges to train the boundry layer into the inlet. The full profile=20 defined by the NACA is rarely used. Most of the inlets we see are some attem= pt=20 at looking like a NACA inlet, without the trouble of actually BEING a NACA=20 inlet. We used to call this "eyeball engineering." Aircooled engines do work= =20 better with NACA inlets as there is less pressure differential than with a=20 radiator. This doesn't mean they will never work, just that the NACA didn't=20 recomend their use with a radiator/heat exchanger.

Bill Jepson

In a message dated 3/9/2006 8:24:30 PM Pacific Standard Time,=20 atlasyts@bellsouth.net writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>John,=20 would you stop calling it a NACA scoop. Remove the big raised
li= p=20 and make it flat. Than come and report to us. Your inlet is half =20
submerged and half raised scoop. NACA is a flush with the surface = ;=20
SUBMERGED inlet.
Buly

On Mar 9, 2006, at 10:44 PM, John=20 Slade wrote:

> Dave,
> My only cooling intake is the plans= =20 Cozy IV NACA.
> Cooling has never been a problem.
>=20 Regards,
> John
>
> David Staten wrote:
>> At t= he=20 risk of invoking PL's name, anyone else read this months
>>= ;=20 Sport Aviation mag from EAA, and notice an article on cooling that =20
>> seems to indicate that NACA's are acceptable and adequate=20 for
>> aircraft cooling needs? I have no idea regarding th= e=20 authors
>> credentials, and I no longer monitor PL's=20 "newsletter".. I was
>> curious more than anything else...= =20 Pauls reaction, others
>> reactions,=20 etc.
>>
>> Translation.. yes.. I'm stirring the=20 pot/Trolling... I figure if
>> we are using NACA's on the=20 Velocity, that makes us somewhat of a
>> NACA=20 supporter..
>>
>> Dave

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