X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.23.0 (ClamAV engine v0.103.0) X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: " 12348ung@gmail.com" Received: from mail-pj1-f47.google.com ([209.85.216.47] verified) by logan.com (CommuniGate Pro SMTP 6.3.5) with ESMTPS id 154866 for flyrotary@lancaironline.net; Wed, 21 Jul 2021 02:48:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.216.47; envelope-from=12348ung@gmail.com Received: by mail-pj1-f47.google.com with SMTP id x13-20020a17090a46cdb0290175cf22899cso456324pjg.2 for ; Tue, 20 Jul 2021 23:48:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:references:in-reply-to:subject:date:message-id:mime-version :thread-index:content-language; bh=weB7pWFMQZ0+QexABEhjojHpCdHMgPl2X9DU0j0w5cY=; b=A0vnZbQmS16LY95ZuP8rI3h2Sc0IlnzPyKfs/erNSRF3TffyX1v8D6V2T3+N1hk9+w 2aSwonmbH9muKMWh5/GDxghrZmKB9N/0mpdJAgfloVDbP2k+gcXVegcQ08InvIWBA064 KBTx70VbOqEDyvPo02XXaJgEoXUWpIqNpybCYO/gukbnbWlhgQLrPi/b+2pjmAm6VzEw K6vyTkYMJAMtuY7HZ9mf1PXl5d7j+feD7P9bw2g5j/Ob6YRb+bkHH80N0gAv6cnx+tSh nPvCZS0aDUN6zrFRcV0fuZHDmDgW3BYeMVz6zwNNbPL4z3ppn5u7zeSleiPiwEwi9A12 GNOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:references:in-reply-to:subject:date :message-id:mime-version:thread-index:content-language; bh=weB7pWFMQZ0+QexABEhjojHpCdHMgPl2X9DU0j0w5cY=; b=lfeZXTR1wAWcLU7h69hlradXPsFBYZxRYddppvXkW/XJiPFhR37MEoi6Cj5GxXGU+G ttLEf4YXqVlthGS8Wv85sQeMFV1vh11wsnXDFdFsdIqjAX5CmPzOUBoCN4L2Cj5jvNbd L4zJDpFS3WRUcxZ/Wspkq3Ua+mUtOKyBjcQbEsfGDIADpOTo7H5zugITphcfbbpvn5HG rZW26B8x3QrzTGM9EPfFwZtBgEUK/vXFLsFCTxDngzqWb9sUy0MEkq7WsTQPQNLGYAoQ vRMJMaVz/FQ7SUMBZw4kxGT0ZPkTcvD0fu58UAG3/1QH7SL8IU1d3cmetTHmj+ZJauU1 VIJQ== X-Gm-Message-State: AOAM530Bn+0c5t41ZiuYEVfxP513N9ru7qU5ES2iY1YWxcakndZ+da7v iznbY4yqvxeNSTdr+K/8yAVZqgEe/Xo= X-Google-Smtp-Source: ABdhPJyRnJs2+M280/kRrH0VMDvbtvtZ8zpfM3gQb9QIFdtSkT27rZRKLaAtbajYXSanEku/dVk4HQ== X-Received: by 2002:a17:90a:885:: with SMTP id v5mr2410711pjc.54.1626850115760; Tue, 20 Jul 2021 23:48:35 -0700 (PDT) Return-Path: <12348ung@gmail.com> Received: from UserPC ([103.198.24.78]) by smtp.gmail.com with ESMTPSA id a13sm4858449pgt.58.2021.07.20.23.48.34 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Jul 2021 23:48:35 -0700 (PDT) To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Fwd: Inlet cooling article Date: Wed, 21 Jul 2021 16:48:32 +1000 Message-ID: <005a01d77dfc$6d38f980$47aaec80$@gmail.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_005B_01D77E50.3EE50980" X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQJ3OTyjxR5PHw1wiSHG6wTKTvT0XqoNhE0g Content-Language: en-us This is a multipart message in MIME format. ------=_NextPart_000_005B_01D77E50.3EE50980 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Charlie, No, no reference, just what I have read and also = talking to Rad manufacturers such as BWR in Brisbane. You can check it = out by passing your hand through a naked flame. Quickly and there is no = heat transfer. Pass slowly and you will see what the argument is. As = I said the truth is there somewhere and as Lyn so aptly puts it = =E2=80=9CI could well be wrong=E2=80=9D.. =20 Neil. =20 From: Rotary motors in aircraft =20 Sent: Wednesday, July 21, 2021 12:25 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Fwd: Inlet cooling article =20 Hi Neil, Do you have a reference for that? Slowing a medium down so it has time = to absorb the heat seems to conflict with physics as I've been led to = understand it. Charlie On 7/20/2021 5:01 PM, 12348ung@gmail.com = wrote: Charlie, Much wisdom out there, you just have to find the = truth! Max cooling is apparently 30 MPH, so Any faster and it does not = pick up heat before going past. Look at big trucks, that grill is not = only for looks, they slow the air to get max cooling. If too slow they = have a quite large fan that kicks in to drag air through at 30 MPH not = 100! As you say, what do I know =E2=80=93 I have seen too = many that do not work =E2=80=93 without any degree. Neil. =20 From: Rotary motors in aircraft = =20 Sent: Wednesday, July 21, 2021 7:07 AM To: Rotary motors in aircraft = Subject: [FlyRotary] Re: Fwd: Inlet cooling article =20 On 7/20/2021 3:26 PM, Marc Wiese cardmarc@charter.net = wrote: Comments? =20 Subject: Inlet cooling article =EF=BB=BF https://www.kitplanes.com/down-to-earth-40/ Sent from my iPhone I remember the Laboda article about enlarging their cooling inlets, but = not many of the details. This: The plenum receives air through two circular air intake ducts behind the = propeller and squeezes it, Bernoulli-style, so that the air accelerates = across the cylinders and between their fins, carrying the heat back, = down and out an outflow "gate" at the back and bottom of the engine = area, forward of the firewall. Is contrary to everything I've ever read about cooling efficiently. = Faster relative flow will always have higher drag, all else being equal. = Accelerating the air even faster than freestream just sounds crazy. My = understanding is that there's a balancing act between having the room in = an a/c to 'recover' (increase) differential pressure across the heat = exchanger (engine fins, in this case), and causing too much drag from = the air going through the fins too fast (there's aerodynamic drag in the = heat exchanger, just like over the a/c itself). It's surprising to me = that James made the plenum the way he did. The rest sounds like putting = bandaids on stuff. The next-to-last image, of the final inlet, shows = what appears to be a *much* smaller plenum inlet than the cowl ring in = front of it, and a rather sharp edged lip where the plenum starts. It = looks like the air would accelerate until it hits that sharp lip, and = immediately go turbulent, which will kill any pressure recovery and = actually slow flow into the cylinder fins.=20 Most Lyc plenums I've seen (even the ones James made for the 4 cyl = engines) have significant volume above the cylinders with smoothly = expanding ducts feeding the plenum. That allows the air to slow in an = organized fashion, which increases *pressure*, which is what actually = makes the air move through the fins. But what do I know; I have an Economics degree.... Charlie =20 = =20 Virus-free. = = www.avast.com=20 =20 =20 ------=_NextPart_000_005B_01D77E50.3EE50980 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

Charlie,

=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 No, no = reference, just what I have read and also talking to Rad manufacturers = such as BWR in Brisbane.=C2=A0 You can check it out by passing your hand = through a naked flame.=C2=A0 Quickly and there is no heat = transfer.=C2=A0 Pass slowly and you will see what the argument is. = =C2=A0=C2=A0As I said the truth is there somewhere and as Lyn so aptly = puts it=C2=A0 =E2=80=9CI could well be wrong=E2=80=9D..=C2=A0 =

Neil.

 

From: Rotary motors in aircraft = <flyrotary@lancaironline.net>
Sent: Wednesday, July 21, = 2021 12:25 PM
To: Rotary motors in aircraft = <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: = Fwd: Inlet cooling article

 

Hi = Neil,

Do you have a reference for that? Slowing a medium down so = it has time to absorb the heat seems to conflict with physics as I've = been led to understand it.

Charlie

On 7/20/2021 5:01 PM, = 12348ung@gmail.com = wrote:

Charlie,

          =          Much wisdom out there, = you just have to find the truth!   Max cooling is apparently = 30 MPH, so Any faster and it does not pick up heat before going = past.  Look at big trucks, that grill is not only for looks, they = slow the air to get max cooling.  If too slow they have a quite = large fan that kicks in to drag air through  at 30 MPH not = 100!

          =       As you say, what do I know =E2=80=93 I = have seen too many that do not work =E2=80=93 without any = degree.

Neil.

 

From: Rotary motors in aircraft <flyrotary@lancaironline.n= et>
Sent: Wednesday, July 21, 2021 7:07 = AM
To: Rotary motors in aircraft <flyrotary@lancaironline.n= et>
Subject: [FlyRotary] Re: Fwd: Inlet cooling = article

 

On = 7/20/2021 3:26 PM, Marc Wiese cardmarc@charter.net = wrote:

Comments?

 

Subject: Inlet cooling = article

=EF=BB=BF https://www.kitplane= s.com/down-to-earth-40/

Sent = from my iPhone

I remember the Laboda article about enlarging their = cooling inlets, but not many of the details.
This:
The plenum receives air through two circular air intake ducts behind = the propeller and squeezes it, Bernoulli-style, so that the air = accelerates across the cylinders and between their fins, carrying the = heat back, down and out an outflow "gate" at the back and = bottom of the engine area, forward of the firewall.

Is = contrary to everything I've ever read about cooling efficiently. Faster = relative flow will always have higher drag, all else being equal. = Accelerating the air even faster than freestream just sounds crazy. My = understanding is that there's a balancing act between having the room in = an a/c to 'recover' (increase) differential pressure across the heat = exchanger (engine fins, in this case), and causing too much drag from = the air going through the fins too fast (there's aerodynamic drag in the = heat exchanger, just like over the a/c itself). It's surprising to me = that James made the plenum the way he did. The rest sounds like putting = bandaids on stuff. The next-to-last image, of the final inlet, shows = what appears to be a *much* smaller plenum inlet than the cowl ring in = front of it, and a rather sharp edged lip where the plenum starts. It = looks like the air would accelerate until it hits that sharp lip, and = immediately go turbulent, which will kill any pressure recovery and = actually slow flow into the cylinder fins.

Most Lyc plenums I've = seen (even the ones James made for the 4 cyl engines) have significant = volume above the cylinders with smoothly expanding ducts feeding the = plenum. That allows the air to slow in an organized fashion, which = increases *pressure*, which is what actually makes the air move through = the fins.

But what do I know; I have an Economics = degree....

Charlie

 

V= irus-free. www.avast.com =

 

 

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