X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-gg0-f180.google.com ([209.85.161.180] verified) by logan.com (CommuniGate Pro SMTP 6.0c2) with ESMTPS id 5804683 for flyrotary@lancaironline.net; Wed, 10 Oct 2012 09:55:19 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.161.180; envelope-from=rwstracy@gmail.com Received: by mail-gg0-f180.google.com with SMTP id q3so101263gge.25 for ; Wed, 10 Oct 2012 06:54:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; bh=SUDPEj7ltS+P1O02XZMUlAVJ7W1ltyh2ne5l6XE0YlQ=; b=0q13qzbEKTcDn63KxAZY1X0mf0xjaUAy5WzWZ4W5tgU92NVWxn8mi7/gO/2FWDXoNF DShPZQx1N+6JBDRF/wYnF4pCQ8EqXq8o5dxdpB5MNyvDrrBrM4yh0JhH4zNK2Zmt7M6F ZYF7bSDTcPvxFnC2JvcMQTnmfKOOxihP3iM7htC4Ejo9FB3dYG45cQVIv2ApTHAYDsdA /iTeCWcDBYm52DYqdG8JE5nPSaEhpCk3FQFX/mKZBpetYVxDMyv3r0h0yaxwF5o/7Emh anJPsi5Rd0qMvqt7NEjmymdluYdT9NdnyQzuUTF9VErqHGevkndBFDHSFyQZBIjwnQbb 6NVA== Received: by 10.236.150.1 with SMTP id y1mr22526924yhj.96.1349877284652; Wed, 10 Oct 2012 06:54:44 -0700 (PDT) Return-Path: Received: from [192.168.1.3] (50.sub-70-196-196.myvzw.com. [70.196.196.50]) by mx.google.com with ESMTPS id f15sm1042518anm.9.2012.10.10.06.54.36 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 10 Oct 2012 06:54:43 -0700 (PDT) Subject: Re: [FlyRotary] Re: cooling airflow concepts References: From: Tracy Content-Type: multipart/alternative; boundary=Apple-Mail-71926990-90AD-43C1-A97D-B30A8CF536B7 X-Mailer: iPad Mail (10A403) In-Reply-To: Message-Id: Date: Wed, 10 Oct 2012 07:54:26 -0600 To: Rotary motors in aircraft Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-71926990-90AD-43C1-A97D-B30A8CF536B7 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Hi Steve, out here in Colorado again with limited access to internet. So= mewhere in the archives is the report I did on the inlets. They were based o= n a NACA study which mainly defined the optimum inner and outer radius for t= he inlets. I found it made a very big difference in capturing off axis air= flow (climb attitude and prop wash) . The difference between the raw tube i= nlet (like a huge pitot tube) and the radiused inlets was very noticeable, e= specially in climb. They were at least a factor of 2 better at capturing t= he prop wash in static conditions as measured by pressure at the face of the= heat exchangers. Tracy Sent from my iPad On Oct 9, 2012, at 11:45 PM, Stephen Izett wrote: > Thanks Steve > I wonder if Tracy is lurking and can comment on the value of reworking the= cowl inlets? >=20 > Cheers >=20 > Steve Izett > On 10/10/2012, at 1:32 PM, Steven W. Boese wrote: >=20 >> Steve, >> =20 >> I am not the right person to try to answer your question. Having retaine= d the stock Van's cooling inlets for the coolant exchangers with essentially= no diffusers, the result appears to be marginal cooling and high drag. So I= am asking myself the exact same question. >> =20 >> Steve Boese >> RV6A, 1986 13B NA, RD1A, EC2 >> =20 >> =20 >> From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf o= f Stephen Izett [steveizett@me.com] >> Sent: Tuesday, October 09, 2012 6:39 PM >> To: Rotary motors in aircraft >> Subject: [FlyRotary] Re: cooling airflow concepts >>=20 >> Thanks again Steve >>=20 >> My current snout looks similar to the attached image. >> I'm considering going to the trouble of reworking the cowl into two circu= lar duct openings, keeping them as far from the centre of the prop as possib= le. >> Current opening is approx 7'' x 3'' - 21sqin. >> Tracy I believe uses (Water Side) 5 1/4" so - 21sqin. >> Multiply Tracy's by 2/3 (loose a rotor) + a bit for the extra side exhaus= t energy (Renesis) going into the coolant - say 15sqin's or 4 1/2 inch diame= ter. >> The other attached photos are modified Glasair snouts >> What do you think I should consider given the amount of work involved and= the possible improvement factored in? >>=20 >> Cheers >> Steve Izett=20 >=20 --Apple-Mail-71926990-90AD-43C1-A97D-B30A8CF536B7 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Hi Steve,   out here in Colorado a= gain with limited access to internet.   Somewhere in the archives is th= e report I did on the inlets.  They were based on a NACA study which ma= inly defined the optimum inner and outer radius for the inlets.   I fou= nd it made a very big difference in capturing off axis airflow (climb attitu= de and prop wash) .  The difference between the raw tube inlet (like a h= uge pitot tube) and the radiused  inlets was very noticeable, especiall= y in climb.   They were at least a factor of 2 better at capturing the p= rop wash in static conditions as measured by pressure at the face of the hea= t exchangers.

Tracy

Sent from my iPad=

On Oct 9, 2012, at 11:45 PM, Stephen Izett <steveizett@me.com> wrote:

Thanks Steve
I wonde= r if Tracy is lurking and can comment on the value of reworking the cowl inl= ets?

Cheers

Steve Izett
On 10/10/2012, at 1:32 PM, Steven W. Boese wrote:

Steve,

 

I am not the right person to try to answer your question.  Ha= ving retained the stock Van's cooling inlets for the coolant exchangers with= essentially no diffusers, the result appears to be marginal cooling an= d high drag.  So I am asking myself the exact same question.

 

Steve Boese
RV6A, 1986 13B NA, RD1A, EC2

 

 

From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Stephen Izett [= steveizett@me.com]
Sent:<= span class=3D"Apple-converted-space"> Tuesday, October 09, 2012 6= :39 PM
To: Rotar= y motors in aircraft
Subject: [FlyRotary] Re: cooling airflow concepts

<= div>
Thanks again Steve

My current snout looks s= imilar to the attached image.
I'm considering going to the trouble= of reworking the cowl into two circular duct openings, keeping them as far f= rom the centre of the prop as possible.
Current opening is approx 7= '' x 3'' - 21sqin.
Tracy I believe uses (Water Side) 5 1/4" so - 2= 1sqin.
Multiply Tracy's by 2/3 (loose a rotor) + a bit for the ext= ra side exhaust energy (Renesis) going into the coolant - say 15sqin's or 4 1= /2 inch diameter.
The other attached photos are modified Glasair s= nouts
What do you think I should consider given the amount of work= involved and the possible improvement factored in?

Cheers
Steve Izett 

= --Apple-Mail-71926990-90AD-43C1-A97D-B30A8CF536B7--