X-Virus-Scanned: clean according to Sophos on Logan.com From: Received: from omr-a016e.mx.aol.com ([204.29.186.65] verified) by logan.com (CommuniGate Pro SMTP 6.1.11) with ESMTPS id 8754812 for flyrotary@lancaironline.net; Thu, 23 Jun 2016 14:03:13 -0400 Received-SPF: pass receiver=logan.com; client-ip=204.29.186.65; envelope-from=Lehanover@aol.com Received: from mtaomg-mcb01.mx.aol.com (mtaomg-mcb01.mx.aol.com [172.26.50.175]) by omr-a016e.mx.aol.com (Outbound Mail Relay) with ESMTP id 92F9A38000BD for ; Thu, 23 Jun 2016 14:02:54 -0400 (EDT) Received: from core-mdd01h.mail.aol.com (core-mdd01.mail.aol.com [172.27.62.11]) by mtaomg-mcb01.mx.aol.com (OMAG/Core Interface) with ESMTP id 0F99C38000087 for ; Thu, 23 Jun 2016 14:02:54 -0400 (EDT) Full-name: Lehanover Message-ID: <1bdb0f.692a2f31.449d7e4c@aol.com> Date: Thu, 23 Jun 2016 14:02:53 -0400 Subject: Re: [FlyRotary] Re: rebuild To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_1bdb0f.692a2f31.449d7e4c_boundary" X-Mailer: AOL 9.8 sub 2019 X-Originating-IP: [74.140.106.236] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1466704974; bh=cDQ/6Lp3r3iBv54o2fAjrdZrf9grBfF4Avg4maR8SaA=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=4Wx3507bNQ5QYO4TAUfnWXxgX6rbWdcCvtPN6tlCYZjQe/7TNWGI84lrmDTgAc0jh CI4bKtpcA9P4AAJUc7kx50iZl238/5YwwEBZtOiVwm/gW1R2GE8jP93QTtixNgaPXT CKDlgcXt3fEW/hdBvT10UfRqSer3/X9lR/v0m5+g= x-aol-sid: 3039ac1a32af576c244e2534 --part1_1bdb0f.692a2f31.449d7e4c_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit I used to buy rotary engines off of the "Core" pile at the junk yard. $50.00 each. You would get enough good pieces for a running engine out of three such engines. You take the bad parts back and sell them by weight. Lynn E. Hanover In a message dated 6/23/2016 12:50:21 P.M. Eastern Daylight Time, flyrotary@lancaironline.net writes: On 6/23/2016 9:52 AM, Andrew Martin wrote: > Thankyou for your replies, makes it a lot easier to make sense of > whats going on, looks like I do need much more inlet area, > maybe just too much optimised for cruise, not much good if I just cant > get there in the first place though. > > Good to hear your system is operating ok Bobby. An early photo of your > setup on flyrotary is what I based mine on. Albeit a lower power > system being NA Renesis. Don't suppose you also have air temp delta's > to go along with the airflow data areas on your radiators. Would be > interesting to know the actual btu's for comparison. > > I'm now thinking my best bet to try next, is to use current duct > solely for the radiator and feed the oil with a new duct somehow, then!! > Andrew > > > -- > Regards > Andrew Martin > Martin Ag Andrew, If it will help you get more comfortable with a large inlet, here are a few quick & dirty points about cooling drag. Some research papers have indicated that as long as the 'lip' around the inlet is shaped correctly (basically a large radius lip), you can make the inlet significantly oversized without affecting drag by a noticeable amount. The way you do it is to control the *exit* size (cowl flap). With the exit flap open, you get large flow, more cooling, and a bit of drag during high power operation (climbs). Closing down the exit flap 'throttles' the flow, letting the excess air volume divert around the inlet rather than flowing through the cooling path. Doing this can simplify duct design and/or improve performance, because 'pressure recovery' happens in front of the inlet, instead of within the duct, where trying to turn the air at high speed or expand it is difficult to do without causing turbulence inside the duct, which increases drag and impedes cooling air flow. I'm sure that others here are more technically qualified to describe it, but as I said, this is the Q&D version. On the subject of separate ducts: IIRC, some have found that even with separate inlet ducts, if the coolers dump into the same space the more free-flowing cooler can still rob flow from the other. Not always a problem, but can be. Charlie -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html --part1_1bdb0f.692a2f31.449d7e4c_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
I used to buy rotary engines off of the "Core" pile at the junk= yard.=20 $50.00 each. You would get enough good pieces for a running engine out of= three=20 such engines. You take the bad parts back and sell them by weight.
Lynn E. Hanover 
 
In a message dated 6/23/2016 12:50:21 P.M. Eastern Daylight Time,=20 flyrotary@lancaironline.net writes:
On=20 6/23/2016 9:52 AM, Andrew Martin wrote:
> Thankyou for your replie= s,=20 makes it a lot easier to make sense of
> whats going on, looks li= ke=20 I  do  need much more inlet area,
> maybe just too much= =20 optimised for cruise, not much good if I just cant
> get there in= the=20 first place though.
>
> Good to hear your system is operatin= g ok=20 Bobby. An early photo of your
> setup on flyrotary is what I base= d mine=20 on. Albeit a lower power
> system being NA Renesis. Don't suppose= you=20 also have air temp delta's
> to go along with the airflow data ar= eas on=20 your radiators. Would be
> interesting to know the actual btu's= for=20 comparison.
>
> I'm now thinking my best bet to try next, is= to=20 use current duct
> solely for the radiator and feed the oil with= a new=20 duct somehow, then!!
> Andrew
>
>
> --
>= =20 Regards
> Andrew Martin
> Martin Ag

Andrew,

If= it=20 will help you get more comfortable with a large inlet, here are a
fe= w=20 quick & dirty points about cooling drag.

Some research papers= have=20 indicated that as long as the 'lip' around the
inlet is shaped corre= ctly=20 (basically a large radius lip), you can make
the inlet significantly= =20 oversized without affecting drag by a noticeable
amount. The way you= do it=20 is to control the *exit* size (cowl flap).
With the exit flap open,= you=20 get large flow, more cooling, and a bit of
drag during high power=20 operation (climbs). Closing down the exit flap
'throttles' the flow,= =20 letting the excess air volume divert around the
inlet rather than fl= owing=20 through the cooling path. Doing this can
simplify duct design and/or= =20 improve performance, because 'pressure
recovery' happens in front of= the=20 inlet, instead of within the duct,
where trying to turn the air at= high=20 speed or expand it is difficult to
do without causing turbulence ins= ide=20 the duct, which increases drag and
impedes cooling air flow.

= I'm=20 sure that others here are more technically qualified to describe it, but=20 as I said, this is the Q&D version.

On the subject of separat= e=20 ducts: IIRC, some have found that even with
separate inlet ducts, if= the=20 coolers dump into the same space the more
free-flowing cooler can st= ill=20 rob flow from the other. Not always a
problem, but can=20 be.

Charlie


--
Homepage: =20 http://www.flyrotary.com/
Archive and UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.html
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