X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=G+5i7Os5 c=1 sm=1 tr=0 a=KsrZmAOw/KbjvbDXy+jZnQ==:117 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=x7bEGLp0ZPQA:10 a=A-0mRrAPPO4A:10 a=J70Eh1EUuV4A:10 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=3oc9M9_CAAAA:8 a=hOpmn2quAAAA:8 a=7g1VtSJxAAAA:8 a=sFeV7tl6h5O-SZPFS1IA:9 a=ArJ-ex4YkjDHDqD8:21 a=172VDW9iHq51IvrU:21 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=5F5-3vjNjiorbEIZyDUA:9 a=CJtk_Nt36QmPCVvw:21 a=wVrjyGtuTykHsBSm:21 a=zM0r3NejBIBodhRA:21 a=Urk15JJjZg1Xo0ryW_k8:22 a=GyA-uvUxXSCciAkwuKQO:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "Charlie England ceengland7@gmail.com" Received: from mail-io1-f52.google.com ([209.85.166.52] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 12931458 for flyrotary@lancaironline.net; Fri, 06 Sep 2019 14:27:10 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.166.52; envelope-from=ceengland7@gmail.com Received: by mail-io1-f52.google.com with SMTP id h144so14838872iof.7 for ; Fri, 06 Sep 2019 11:27:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=XSxBCcgpJbVfSTRPcnm8QLHb3Kedx8ZCGkCKjBABNmA=; b=GszyjWHkJI8xDtzJlCO2UNpnDt0BI/835+VbWHDIPOlvV8J8lsNAbGedV9P0LQKjLu 9QsirlEfVhEdIgNeTERjRo5W8FGLPh6m7XkuVwd7FapilFx4cU3dTyIYF0coupLg8W+Q 8phKdSqJOq3k7Y9WOUw0wM8x2SER8pigyu6lBB0H7OdI6udayQS6u6V8qzMHnOXqJ3UD +dgaWdows6+j33NOV8sZSgrMtycr4EEJvVyLvDIVg57toWU3DcSL3EK2F44g/43J5pgh XEcqJkD0JV7K8CBj1plNeHlm+yiZg5PLzvzZocK3MgGF0W5/aHnrV1BkGU/0NJC+T8hE 1paA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=XSxBCcgpJbVfSTRPcnm8QLHb3Kedx8ZCGkCKjBABNmA=; b=j3sHwvfLYkJ3p4qHsytb8Df703WvonwRZaZdyLtgxlp7s2h++mrenYwC20hvps8pRH BbduNBht5lhr/vc9xu8dmpivlJgvF9P9nsaY5zJXGXtEoq57h16+tzSIUq5K+JAu3l8O RkHxAWL/Q0naOdMuKkuSzJHn29pTqdVu+RXFFLQ1N8wq1XLxy7nr7stgMeivq9uZLa8H rVCSqWL7xtTXgVMs+66yBV8r5ageBSUNda00IX+0furZxgkxIHmHP1NI6kaRFUGk6TxT LOL2c5pOlyD8wrlLXRGQ0XEhVDHbo30P278ZvbtdhWvFH68yMvxNFMUEAoi4Xax1anrV N/Ew== X-Gm-Message-State: APjAAAXDeR+A05QG77uERz695pTDs8TN2KHB3n5hfF1D4DFEYe//0tuM SgdgaOrIw+8HGETKNDJoGXtMD8INZ4PsKfq/ZHfhPA== X-Google-Smtp-Source: APXvYqyRmg6X5cVfAgsO9V2B8lOsuGHZk/pc77CCiuQ1M1h7CFrkjc9wMcup0zrQzZppKNWuQWZp0cPEaDdwK7Yg8Ss= X-Received: by 2002:a02:a99d:: with SMTP id q29mr11924598jam.80.1567794412403; Fri, 06 Sep 2019 11:26:52 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: Date: Fri, 6 Sep 2019 13:19:32 -0500 Message-ID: Subject: Re: [FlyRotary] Re: Part specs-radiator design To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="0000000000000840030591e69569" --0000000000000840030591e69569 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I've never experimented with minimal angles off perpendicular; those may not matter much. But at some point, you end up with a 'wedge' diffuser, and then the shape of the wedge becomes important. Finn, look at K&W chapter 12; section 12-2 deals with 'oblique flow'. BTW, figure 12-12 in that chapter doesn't seem to jive with real world experiments. Tracy found, and warned me about, the need to pinch the aft end of a wedge significantly to avoid the vast majority of the flow happening in the aft third of the core. It's impressive how much pinch is needed to keep flow even across the core. Charlie On Fri, Sep 6, 2019 at 1:05 PM William Jepson wrjjrs@gmail.com < flyrotary@lancaironline.net> wrote: > Rich. I said =E2=80=9Cif the airflow is there=E2=80=9D. The question I wa= s answering was > about the angle of the heat exchanger. We do need to be sure we don=E2=80= =99t trap > air inside, and of course that there is actual airflow through. Many of o= ur > rotary installs would be helped by using manometers to check if the area > behind the radiators are lower pressure. Motorcycles are another =E2=80= =9Cspecial > case=E2=80=9D since most require the air to turn 90 degrees to exit the f= airing. > The only really excellent design on bikes was the Britten. I raced > motorcycles in the past and the only different configuration I saw was th= e > Honda RC 51. ( if I have the right number) with both radiators in the che= ek > position in the fairing. > Bill Jepson > > On Fri, Sep 6, 2019 at 10:44 AM A R Goldman argoldman@aol.com < > flyrotary@lancaironline.net> wrote: > >> Not totally true as I learned from overheating my norton rotary >> dragonfly. It makes sense that air flows from high pressure to low. But. >> Many times oh has a mind of its own counterintuitively. For example as t= he >> air exit the exchanger if it is not allowed to exit straight or gently >> deflected, independent of the delta the air will stagnate and not go whe= re >> you expect. Pay as much attention to the exit as you do with the entry >> >> Yrmv >> >> Rich >> >> Sent from my iPhone >> >> On Sep 6, 2019, at 11:52 AM, William Jepson wrjjrs@gmail.com < >> flyrotary@lancaironline.net> wrote: >> >> Answer is nothing; provided the airflow is there. Also there needs to be >> a vent or tap to get all the air out of the inside. >> Bill Jepson >> >> On Fri, Sep 6, 2019 at 8:38 AM Marc Wiese cardmarc@charter.net < >> flyrotary@lancaironline.net> wrote: >> >>> Finn asks- >>> "BTW, what happens when you lay down (at a 20 degree) angle a radiator >>> that is designed to be upright?" >>> >>> I always wondered about that myself. The stock FD (3rd gen) radiator ha= s >>> to be at about a 45 degree angle (?) to the incoming airstream. And it = has >>> 2 "supplemental" staged electric fans (no pump fan), one is always on i= f >>> the AC is on, the fans have different blades and different speeds >>> controlled by ECU and temp sensor. I suppose the fins are canted or per= haps >>> they are best tilted to airflow to create turbulence and help remove so= me >>> heat..........don't know much about radiator design............ >>> MW >>> >>> -- >>> Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: >>> http://mail.lancaironline.net:81/lists/flyrotary/List.html >>> >>> >>> -- >>> Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: >>> http://mail.lancaironline.net:81/lists/flyrotary/List.html >>> >> --0000000000000840030591e69569 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I&#= 39;ve never experimented with minimal angles off perpendicular; those may n= ot matter much. But at some point, you end up with a 'wedge' diffus= er, and then the shape of the wedge becomes important. Finn, look at K&= W chapter 12; section 12-2 deals with 'oblique flow'. BTW, figure 1= 2-12 in that chapter doesn't seem to jive with real world experiments. = Tracy found, and warned me about, the need to pinch the aft end of a wedge = significantly to avoid the vast majority of the flow happening in the aft t= hird of the core. It's impressive how much pinch is needed to keep flow= even across the core.

Ch= arlie

On Fri, Sep 6, 2019 at 1:05 PM William Jepson wrjjrs@gmail.com <flyrotary@lancaironline.net> wrote:
Rich. I sa= id =E2=80=9Cif the airflow is there=E2=80=9D. The question I was answering = was about the angle of the heat exchanger. We do need to be sure we don=E2= =80=99t trap air inside, and of course that there is actual airflow through= . Many of our rotary installs would be helped by using manometers to check = if the area behind the radiators are lower pressure. Motorcycles are anothe= r =E2=80=9Cspecial case=E2=80=9D since most require the air to turn 90 degr= ees to exit the fairing. The only really excellent design on bikes was the = Britten. I raced motorcycles in the past and the only different configurati= on I saw was the Honda RC 51. ( if I have the right number) with both radia= tors in the cheek position in the fairing.
Bil= l Jepson

On Fri, Sep 6, 2019 at 10:44 AM A R Goldman argoldman@aol.com <flyrotary@lancaironlin= e.net> wrote:
Not totally true as I learned from overheating my no= rton rotary dragonfly. It makes sense that air flows from high pressure to = low. But. Many times oh has a mind of its own counterintuitively. For examp= le as the air exit the exchanger if it is not allowed to exit straight or g= ently deflected, independent of the delta the air will stagnate and not go = where you expect. Pay as much attention to the exit as you do with the entr= y

Yrmv

Rich

Sent from my iPhone

On Sep 6, 2019, at 11:52 AM, William Jepson wrjjrs@gmail.com <flyrotary@lancaironline.= net> wrote:

=
Answer is nothing; provided the airflow is there. Al= so there needs to be a vent or tap to get all the air out of the inside.
Bill Jepson=C2=A0

On Fri, Sep 6, 2019 at 8:3= 8 AM Marc Wiese c= ardmarc@charter.net <flyrotary@lancaironline.net> wrote:
Finn asks-
"BTW, what happens when you lay down (at a 20 degree) angle a radiator= that is designed to be upright?"

I always wondered about that myself. The stock FD (3rd gen) radiator has to= be at about a 45 degree angle (?) to the incoming airstream. And it has 2 = "supplemental" staged electric fans (no pump fan), one is always = on if the AC is on, the fans have different blades and different speeds con= trolled by ECU and temp sensor. I suppose the fins are canted or perhaps th= ey are best tilted to airflow to create turbulence and help remove some hea= t..........don't know much about radiator design............
MW

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