Return-Path: Received: from seraph2.grc.nasa.gov ([128.156.10.11] verified) by logan.com (CommuniGate Pro SMTP 4.2b8) with ESMTP id 323385 for flyrotary@lancaironline.net; Fri, 16 Jul 2004 09:23:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=128.156.10.11; envelope-from=Joseph.M.Berki@grc.nasa.gov Received: from lombok-fi.grc.nasa.gov (lombok-fi.grc.nasa.gov [139.88.112.33]) by seraph2.grc.nasa.gov (Postfix) with ESMTP id 3406C68994 for ; Fri, 16 Jul 2004 09:23:23 -0400 (EDT) Received: from manihi.grc.nasa.gov (manihi.grc.nasa.gov [139.88.112.36]) by lombok-fi.grc.nasa.gov (NASA GRC TCPD 8.12.10/8.12.10) with ESMTP id i6GDNMIM027265 for ; Fri, 16 Jul 2004 09:23:22 -0400 (EDT) Received: from GR7700013583.lerc.nasa.gov (gr7700013583.grc.nasa.gov [139.88.139.62]) by manihi.grc.nasa.gov (NASA GRC TCPD 8.12.10/8.12.10) with ESMTP id i6GDNM8W025559; Fri, 16 Jul 2004 09:23:22 -0400 (EDT) X-Info: ODIN / NASA Glenn Research Center Message-Id: <5.1.1.5.2.20040716092006.01771840@popserve.lerc.nasa.gov> X-Sender: scberki@popserve.lerc.nasa.gov X-Mailer: QUALCOMM Windows Eudora Version 5.1.1 Date: Fri, 16 Jul 2004 09:23:18 -0400 To: "Rotary motors in aircraft" From: Joseph M Berki Subject: Re: [FlyRotary] Re: New Scoop Cc: "Rotary motors in aircraft" In-Reply-To: Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="=====================_160629250==.ALT" --=====================_160629250==.ALT Content-Type: text/plain; charset="us-ascii"; format=flowed Al, Another concern about placing these heat exchangers in the wing is what happens after shut down and the blue foam in the wing experiences heat soak as the exchangers cool? Did you isolate the mounting from the composite? High temp resin in the close out? Just a thought. Joe Berki Limo EZ At 09:14 PM 7/15/2004 -0700, Al Gietzen wrote: >Subject: [FlyRotary] Re: New Scoop > > > >Al, > >I don't know exactly how to phrase this question but I'll take a stab at it. > >When you decided to place the heat exchangers in the wings how did you >estimate > >the effect(if any) due to impact on the designed airfoil(s)? I think this is a > >great place for them in the canard designs. I am thinking about the spaces in > >the rear of the strakes for mine. > >Dean Head > >Cozy MK4 > >BKV FL > > > >Dean; > > > >You probably phrased the question better than I can phrase the answer. > > > >Actually; I wasn t very concerned about airfoil effects because on the >canards the strake is not a very effective lifting surface because of the >very high Reynold s number. It is designed for neutral angle of attack at >cruise, with essentially all the lift provided by the canard and >wings. There is some pressure differential between upper and lower >surface (based on aerodynamic analysis) in the wing rot behind the strake >which can help the flow through the coolers, and the difference is greater >at higher angles of attack, when you need the flow the most. I pushed my >strake tops up a bit during installation increase the effect, as well as >give me a bit more fuel capacity. I guessed no; ah-h, applied my >engineering judgement that the amount of flow through the cooler would not >significantly impact the lift. > > > >I designed the exit faring like the upper half of an airfoil to retain >attached flow to minimize the turbulence generated behind the faring. > > > >I really don t know yet how well it is going to work. Is that why they >call these experimental aircraft ? The only data point we have is Alan >Shaw s oil cooler installation, which apparently worked well even though >his approach to the airflow was not as; let s say, sophisticated as mine. > > > >Al --=====================_160629250==.ALT Content-Type: text/html; charset="us-ascii" Al,
Another concern about placing these heat exchangers in the wing is what happens after shut down and the blue foam in the wing experiences heat soak as the exchangers cool? Did you isolate the mounting from the composite? High temp resin in the close out? Just a thought.

Joe Berki
Limo EZ

At 09:14 PM 7/15/2004 -0700, Al Gietzen wrote:

Subject: [FlyRotary] Re: New Scoop

Al,

I don't know exactly how to phrase this question but I'll take a stab at it.

When you decided to place the heat exchangers in the wings how did you estimate

the effect(if any) due to impact on the designed airfoil(s)? I think this is a

great place for them in the canard designs. I am thinking about the spaces in

the rear of the strakes for mine.

Dean Head

Cozy MK4

BKV FL

Dean;

You probably phrased the question better than I can phrase the answer.

Actually; I wasn t very concerned about airfoil effects because on the canards the strake is not a very effective lifting surface because of the very high Reynold s number. It is designed for neutral angle of attack at cruise, with essentially all the lift provided by the canard and wings. There is some pressure differential between upper and lower surface (based on aerodynamic analysis) in the wing rot behind the strake which can help the flow through the coolers, and the difference is greater at higher angles of attack, when you need the flow the most. I pushed my strake tops up a bit during installation increase the effect, as well as give me a bit more fuel capacity. I guessed no; ah-h, applied my engineering judgement that the amount of flow through the cooler would not significantly impact the lift.

I designed the exit faring like the upper half of an airfoil to retain attached flow to minimize the turbulence generated behind the faring.

I really don t know yet how well it is going to work. Is that why they call these experimental aircraft ? The only data point we have is Alan Shaw s oil cooler installation, which apparently worked well even though his approach to the airflow was not as; let s say, sophisticated as mine.

Al

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