X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-ew0-f52.google.com ([209.85.215.52] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4586735 for flyrotary@lancaironline.net; Sat, 20 Nov 2010 21:42:48 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.215.52; envelope-from=msteitle@gmail.com Received: by ewy4 with SMTP id 4so3679953ewy.25 for ; Sat, 20 Nov 2010 18:42:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=xYD6IMSxa7nzU7Lg2pXKmmnP3sNH9/EmNxETaShUJsE=; b=UojC0eWFr+tcHYamlzZDYdgOmZuflB+NmQcx8y5qWFHL5c9G2IZyFHU0ajzLBwqEdj mlrXsZRC5k96+LThX+nDAyoyXv6UpG8JsUiohoUi2W81FndS0/I1FBX6MTiAvKypfiV2 Fbfan7EK/a+8R1zvMCs56hIYF6L+vs3/uTTk0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=iVwWwRCYoLpX8F/z1G/EV8qrYNHhf6dbI625rM6kRJL/Krp3oBvncXuSVWpTFc8h2b rLZLcSoF8eRsCqmLuQ/SBAFhnXbPlUc8pWNN6UsNX1VOqEmMCr6Q/Cm4K3oQevo/2HYj 7dOO51aICg7ScVvREcPttyM51jhObsue3pid4= MIME-Version: 1.0 Received: by 10.213.17.139 with SMTP id s11mr3142516eba.51.1290307331140; Sat, 20 Nov 2010 18:42:11 -0800 (PST) Received: by 10.213.36.17 with HTTP; Sat, 20 Nov 2010 18:42:11 -0800 (PST) In-Reply-To: References: Date: Sat, 20 Nov 2010 20:42:11 -0600 Message-ID: Subject: Re: [FlyRotary] Re: Exhaust Calcuations From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015174c3d6a1fabe7049587167d --0015174c3d6a1fabe7049587167d Content-Type: text/plain; charset=ISO-8859-1 Charlie, I can't argue with that logic. But if you tune so that you have enough hp to go fast, then surely you'll have enough to fly slow too. This analogy doesn't work in reverse. You never know when you'll have to blow the doors off a Lycosarus, just because you can. Mark On Sat, Nov 20, 2010 at 7:41 PM, Charlie England wrote: > My thought is to take a somewhat different approach to tuning. My desire > would be to tune for intended cruise rpm. My reasoning is that just about > all homebuilt designs that will run a rotary will have excess power anyway, > so why not tune for max efficiency at the rpm where the the engine will > spend 95%+ of its time? Even more applicable if a controllable prop is > available. > > Can anyone see any problem with that logic? > > Charlie > > > On 11/20/2010 10:18 AM, Mark Steitle wrote: > > Ed, > > OK, that answers my question. By going with 1-7/8" OD pipe (.049 wall), > it would be tuned for about 7800 rpm. Obviously, this is too high for our > purposes. I'll go with 1-5/8 (.063 wall) to shoot for 6700 rpm peak power. > This is typically the rpm I see on ground roll and early climb before I > start adjusting the prop down to a lower rpm to transition to cruise climb. > > Have you used the header designer tool available from Burns Stainless? > You need to know all the timing numbers, rpm, etc. I may give it a try and > see what I come up with. I have a test p-port housing that I made up to see > if the tube could be welded to the inner liner. So, I can use that with a > spare rotor to verify the EVO and EVC numbers. > > Mark > > > On Sat, Nov 20, 2010 at 9:55 AM, Ed Anderson wrote: > >> Mark, >> >> Here is the corrected spreadsheet - I've colored the changeable cells blue >> - you can plug in any rpm and EVO. The rest of the cells are protected to >> keep from accidently overwriting them. >> >> Ed >> >> Edward L. Anderson >> Anderson Electronic Enterprises LLC >> 305 Reefton Road >> Weddington, NC 28104 >> http://www.andersonee.com >> http://www.eicommander.com >> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >> >> > > --0015174c3d6a1fabe7049587167d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Charlie,=A0

I can't argue with that logic. =A0But if= you tune so that you have enough hp to go fast, then surely you'll hav= e enough to fly slow too. =A0This analogy doesn't work in reverse. =A0Y= ou never know when you'll have to blow the doors off a Lycosarus, just = because you can.=A0

Mark =A0 =A0

On Sat, = Nov 20, 2010 at 7:41 PM, Charlie England <ceengland@bellsouth.net> wrote= :
=20 =20 =20 =20
My thought is to take a somewhat different approach to tuning. My desire would be=A0 to tune for intended cruise rpm. My reasoning is that just about all homebuilt designs that will run a rotary will have excess power anyway, so why not tune for max efficiency at the rpm where the the engine will spend 95%+ of its time? Even more applicable if a controllable prop is available.

Can anyone see any problem with that logic?

Charlie


On 11/20/2010 10:18 AM, Mark Steitle wrote:
Ed,

OK, that answers my question. =A0By going with 1-7/8" OD pi= pe (.049 wall), it would be tuned for about 7800 rpm. =A0Obviously, this is too high for our purposes. =A0I'll go with 1-5/8 (.063 wall) to shoot for 6700 rpm peak power. =A0This is typically the rpm I see on ground roll and early climb before I start adjusting the prop down to a lower rpm to transition to cruise climb.

Have you used the header designer tool available from Burns Stainless? =A0You need to know all the timing numbers, rpm, etc. =A0I may give it a try and see what I come up with. =A0I have a test p-port housing that I made up to see if the tube could be welded to the inner liner. =A0So, I can use that with a spare rotor to verify the EVO and EVC numbers. =A0
=A0
Mark


On Sat, Nov 20, 2010 at 9:55 AM, Ed Anderson <eanderson@carolina.rr.com> wrote:
Mark,
=A0
Here is the corrected spreadsheet - I've colored the changeable cells blu= e - you can plug in any rpm and EVO.=A0 The rest of the cells are protected to keep from accidently overwriting them.
=A0
Ed
=A0
Edward L. Anderson
Anderson Electronic Enterprises LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

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




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