X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-gw0-f52.google.com ([74.125.83.52] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTPS id 4999488 for flyrotary@lancaironline.net; Tue, 31 May 2011 16:09:20 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.125.83.52; envelope-from=editor.contactmagazine@gmail.com Received: by gwj15 with SMTP id 15so2852842gwj.25 for ; Tue, 31 May 2011 13:08:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:reply-to:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=sFdB6CtWrJlAJI2poQm1rNbk1HEjSZrjHvP2HFmnnxk=; b=BD7FlaEzRPfnu0zxNGnL9I19fCNBUgOGj0Gpx7jGp2SrwNraZW0fa0RBAsHeuJ5cRT uZ6Isg3YXB2r8Wn2ItBgqZIF3lmpilH9MMedVWBrB9HVoZYNenHFSPDEdMCqG/USJ0s7 S4LZpIJZUnxFRq5lKeGy1JqV/lqvqBTXuqmag= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:reply-to:in-reply-to:references:date:message-id :subject:from:to:content-type; b=uLQ2QW89Hog0FMG9cBPkwSen2n9LlMin007zkx50e4DYqy0cvgz2D4jRo+8x4pvzm9 9tkKe2pDBQ2WclIXBZ7bYHmkNnoku8gY8m4iYFukK77FLBfmLZqq5LGTzZyu3uH0XghR Z8ZZ7MU1q0ij8HljjL/zjLNxIrZGmD7w91Bes= MIME-Version: 1.0 Received: by 10.236.195.40 with SMTP id o28mr7399470yhn.378.1306872525078; Tue, 31 May 2011 13:08:45 -0700 (PDT) Received: by 10.236.155.8 with HTTP; Tue, 31 May 2011 13:08:45 -0700 (PDT) Reply-To: panzera@experimental-aviation.com In-Reply-To: References: Date: Tue, 31 May 2011 13:08:45 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Blower design From: Pat Panzera To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=20cf305b0a349fc25804a497f82f --20cf305b0a349fc25804a497f82f Content-Type: text/plain; charset=ISO-8859-1 Here's more info that was sent to me: Hi Pat, As you might already know, the stock cooling fan gets discussed (sometimes cussed) quite a bit in Corvair car circles. Chevy did tests on the fans, so the HP use isn't a guess, it's documented - you do have to extrapolate the curve, but at 3400, it takes about 7 HP to drive the fan. The later magnesium fans were made to help keep the belt on during enthusiastic driving of a stick shift car, the earlier fans actually flow a little more air per HP. The later fan does use a little less HP total, but it also flows less air, the fan design suffered a bit so it could be a cast rather than a built up assembly. More info on my site at: http://autoxer.skiblack.com/fan.html Hope that helps. --Bryan On Tue, May 31, 2011 at 1:02 PM, Ernest Christley wrote: > Pat Panzera wrote: > >> Here's some info on the HP required to run the Corvair fans. >> http://corvaircenter.com/phorum/read.php?1,395865,page=1 >> >> One of the early Corvair designs, made from steel. It's heavy at >> 8 lbs, but I'll be cutting away a large portion of it, and if it >> works as well as I hope I'll keep searching for something lighter. >> >> Cost me $7. The shipping was $13.50 8*) >> >> >> Oh, if I could only be so lucky to have it eat 27Hp. 8*). > > All my numbers are from memory here, 'cause I'm at work and I'm not going > to look them all up again. But they should be close enough to get the idea > across. > > At 6000RPM, the 13B will let 275cfm of 14.7 psi air pass at 100% VE. At > 6000rpm, this fan will require somewhere around 20Hp and move 2700cfm of > air. For all intents, the engine is going to look like a big blockage. The > fan will pump up the static pressure as high as its tip speed will allow, > and then will just keep moving the same air around in a circle. The latter > activity will require very little energy. Other calculations that I've done > show that moving the 275cfm at the 80m/s tip speed that I'll get out of > 10.5" will take about 4Hp. I could be wrong. > > How will I test all this? > > Step 1: Put the blower all together with the exit blocked and mount it in > my drill press. It only has a 1Hp motor, but I won't actually be moving > much air. That will tell me what the maximum static pressure I can get at > about 4300RPM, the maximum I can get out of the drill press. > > Step pre-2: Tune the engine to get it running somewhat reasonably well for > the follow on test. > > Step 2: With the blower on the engine, record the manifold pressure at > speed with intake removed from the blower. I have an elbow in the intake > system that I can simply turn around, so this is easy. > > Step 3: Shut the engine down. Turn the elbow around to bring the blower > into play, then crank 'er back up. > > The data logs will show whether I've wasted my time or not. > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > --20cf305b0a349fc25804a497f82f Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Here's more info that was sent to me:




<= /div>
Hi Pat,

As you might already know, the stock cooling fan gets discussed (someti= mes cussed) quite a bit in Corvair car circles. =A0Chevy did tests on the f= ans, so the HP use isn't a guess, it's documented - you do have to = extrapolate the curve, but at 3400, it takes about 7 HP to drive the fan.
The later magnesium fans were made to help keep the belt on during enth= usiastic driving of a stick shift car, the earlier fans actually flow a lit= tle more air per HP. =A0The later fan does use a little less HP total, but = it also flows less air, the fan design suffered a bit so it could be a cast= rather than a built up assembly.

More info on my site at:

http://autoxe= r.skiblack.com/fan.html

Hope that helps.

--Bryan

On Tue, May 31, 201= 1 at 1:02 PM, Ernest Christley <echristley@nc.rr.com> wrote:
Pat Panzera wrote:
Here's some info on the HP required to run the Corvair fans.
http://corvaircenter.com/phorum/read.php?1,395865,page=3D1

=A0 =A0One of the early Corvair designs, made from steel. =A0It's heav= y at
=A0 =A08 lbs, but I'll be cutting away a large portion of it, and if i= t
=A0 =A0works as well as I hope I'll keep searching for something light= er.

=A0 =A0Cost me $7. =A0The shipping was $13.50 =A08*)


Oh, if I could only be so lucky to have it eat 27Hp. =A08*).

All my numbers are from memory here, 'cause I'm at work and I'm= not going to look them all up again. =A0But they should be close enough to= get the idea across.

At 6000RPM, the 13B will let 275cfm of 14.7 psi air pass at 100% VE. =A0At = 6000rpm, this fan will require somewhere around 20Hp and move 2700cfm of ai= r. =A0For all intents, the engine is going to look like a big blockage. =A0= The fan will pump up the static pressure as high as its tip speed will allo= w, and then will just keep moving the same air around in a circle. =A0 The = latter activity will require very little energy. =A0Other calculations that= I've done show that moving the 275cfm at the 80m/s tip speed that I= 9;ll get out of 10.5" will take about 4Hp. =A0I could be wrong.

How will I test all this?

Step 1: =A0Put the blower all together with the exit blocked and mount it i= n my drill press. =A0It only has a 1Hp motor, but I won't actually be m= oving much air. =A0That will tell me what the maximum static pressure I can= get at about 4300RPM, the maximum I can get out of the drill press.

Step pre-2: Tune the engine to get it running somewhat reasonably well for = the follow on test.

Step 2: =A0With the blower on the engine, record the manifold pressure at s= peed with intake removed from the blower. =A0I have an elbow in the intake = system that I can simply turn around, so this is easy.

Step 3: Shut the engine down. =A0Turn the elbow around to bring the blower = into play, then crank 'er back up.

The data logs will show whether I've wasted my time or not.

--
Homepage: =A0http:/= /www.flyrotary.com/
Archive and UnSub: =A0 http://mail.lancaironline.net:81/lists= /flyrotary/List.html

--20cf305b0a349fc25804a497f82f--