X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4191172 for flyrotary@lancaironline.net; Wed, 31 Mar 2010 20:28:52 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet2.per.eftel.com (Postfix) with ESMTP id 2F6F91736D8 for ; Thu, 1 Apr 2010 08:28:12 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id 6A982BEC02E for ; Thu, 1 Apr 2010 08:28:11 +0800 (WST) Message-ID: <56BB21B9B0554D3898D56BBA5BB20B34@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Tuned lengths? Date: Thu, 1 Apr 2010 10:28:11 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000F_01CAD186.07B00740" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 100331-2, 03/31/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_000F_01CAD186.07B00740 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ben I hear you, sadly, if I read the articles right, the tuning goes to = Zero, 500 rpm above or below the tuning point. So one has to select = their best performance at either take-off or cruise. I would probably = select cruise. George (down under) =20 Yup.... But. The design parameters are alot different for an = application that need usable power from 1500 to 9000 rpm, Like in a = car.. We only need good performance around 5500 - 7000, plus or minus a = little,,who the heck cares how the thing idles or pulls strong at 8900. = . That narrow powerband for aircraft applications is what I was speaking = about. YMMV Ben Haas www.haaspowerair.com =20 -------------------------------------------------------------------------= ----- To: flyrotary@lancaironline.net From: lendich@aanet.com.au Date: Thu, 1 Apr 2010 07:55:40 +1000 Subject: [FlyRotary] Re: Tuned lengths? Ben, I agree tuning is necessary all designs are slightly different. On the subject of intake design, I don't think Mazda came up with = their fancy Renesis intake by chance, I'm pretty sure that would be a = computer proven design, well before production. George (down under) Lynn does such a great job at painting a very clear picture of the = dynamics of an internal combustion engine.. Thank you sir... As a side = note those of us using an engine in close to a steady state application = are very lucky because tuning the intake is alot easier then in a = application that has a wide powerband range. A coupleof sharp motor = tuners and a day or so on a good repeatable dyno can zero in on = acceptable intake design that should set a good baseline for what really = works. You can sliderule / use fancy computer programs and other methods = of determining optimum designs but nothing trumps real time data in a = running engine. Just my .02 cents worth. =20 Ben Haas www.haaspowerair.com -------------------------------------------------------------------------= --- To: flyrotary@lancaironline.net Date: Wed, 31 Mar 2010 01:09:18 -0400 From: lehanover@gmail.com Subject: [FlyRotary] Tuned lengths? A "tuned" intake covers a wide Varity of techniques ranging for = Hermholtz, RAM, Dynamic Intake, Inertia, etc,. There are basically three = conceptually different approaches although they tend to merge under certain = conditions. You have the resonant tuning, the pulse tuning and the inertia = turning concepts. However, truth be known all three phenomena occur in most = intake systems - it's a matter of emphasis. The thing that really complicates it is the fact that within any = induction or exhaust system you have Finite Amplitude Waves - the power of = these pulse makes a 135 db sound wave very puny - these pulses can actually = pound metal apart. They do not interact linearly as do "sound waves" - in fact = they can respond in what at first seems to be weird ways. For instance they = may reverse there "polarity" depending on whether they encounter an open = or closed termination. It has only been with the advent of digital computers has it been = practical to even try and model the effects of these waves in an induction = system. I find them fascinating. Here are a few references that some of you might find interesting. http://home.earthlink.net/~redcat/pulse_ram/theory.html http://www.motionsoftware.com/simtech.htm http://www.proracingsim.com/dynomationmainpage.htm http://www.audietech.com/DMfeaturetable.htm Ed Anderson Side intake port engines produce different tuned effects than do = Periphery ported intake engines.=20 Side exhaust ported engines produce different tuned effects than do = periphery ported exhaust engines. The most powerfull engine would be the Periphery intake and exhaust = ported engines.=20 Although the intake and exhaust open and close events are reported = in degrees of crankshaft rotation just like a side port engine, the periphery ports never actually = close. So, tuned lengths produce bigger changes than in the side ported = engine. So, one end of the tune length is virtually open all of the = time, and worse one end is exposed to changeing pressures all of the = time.=20 The overlap (Intake and exhaust open at the same time) is huge. So = exhaust back pressure can poison the intake quite badly.=20 In the side intake ported engine one end of the column is closed = solid by the side of the rotor. Intake and exhaust overlap may be = minimal or extensive. Column lengths produce crisp tuning. Overlap with = peripheral exhaust ports may have less effect. Exhaust back pressure can = remove much power. Side intake and exhaust Renesis) may have no overlap at all. The = center exhaust ports share an exit that is too large right at the port = face. Even with no overlap, the intake can be poisoned by exhaust gasses = being held in the chamber by a poor exhaust system. Exhaust system has = three outlets Possibly less sensitive to back pressure than other designs When = converted to a Periphery intake port, may still have low overlap.=20 Lynn E. Hanover.=20 =20 -------------------------------------------------------------------------= --- Hotmail: Trusted email with powerful SPAM protection. Sign up now.=20 -------------------------------------------------------------------------= ----- The New Busy is not the old busy. Search, chat and e-mail from your = inbox. Get started. ------=_NextPart_000_000F_01CAD186.07B00740 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ben I hear you, sadly, if I read the articles = right, the=20 tuning goes to Zero, 500 rpm above or below the tuning point. = So one has to=20 select their best performance at either take-off or cruise. I would = probably select cruise.
George (down under)  
Yup....=20 But. The design parameters are alot different for an application that = need=20 usable power from 1500 to 9000 rpm, Like in a car.. We only need good=20 performance around 5500 - 7000,  plus or minus a little,,who the = heck=20 cares how the thing idles or pulls strong at 8900. . That narrow=20 powerband for aircraft applications is what I was speaking = about.=20 YMMV

Ben Haas
www.haaspowerair.com



 
To: flyrotary@lancaironline.net
From: lendich@aanet.com.au
Date: = Thu, 1=20 Apr 2010 07:55:40 +1000
Subject: [FlyRotary] Re: Tuned = lengths?

Ben,
I agree tuning is necessary all designs are = slightly=20 different.
On the subject of intake design, I don't think = Mazda=20 came up with their fancy Renesis intake by chance, I'm pretty sure = that would=20 be a computer proven design, well before production.
George (down under)
Lynn=20 does such a great job at painting a very clear picture of the = dynamics of an=20 internal combustion engine.. Thank you sir... As a side note those = of us=20 using an engine in close to  a steady state application = are very=20 lucky because tuning the intake is alot easier then in a application = that=20 has a wide powerband range. A coupleof sharp motor tuners and a day = or so on=20 a good repeatable dyno can zero in on acceptable intake design that = should=20 set a good baseline for what really works. You can sliderule / use = fancy=20 computer programs and other methods of determining optimum designs = but=20 nothing trumps real time data in a running engine. Just my .02 cents = worth.
 
Ben Haas
www.haaspowerair.com






To: flyrotary@lancaironline.net
Date: Wed, 31 Mar 2010 01:09:18=20 -0400
From: lehanover@gmail.com
Subject: [FlyRotary] Tuned=20 lengths?

A "tuned" intake covers a wide Varity of techniques ranging for = Hermholtz,
RAM, Dynamic Intake, Inertia, etc,.  There are = basically=20 three conceptually
different approaches although they tend to = merge under=20 certain conditions.
You have the resonant tuning, the pulse = tuning and=20 the inertia turning
concepts.  However, truth be known all = three=20 phenomena occur in most intake
systems - it's a matter of=20 emphasis.

The thing that really complicates it is the fact = that=20 within any induction
or exhaust system you have Finite Amplitude = Waves -=20 the power of these pulse
makes a 135 db sound wave very puny - = these=20 pulses can actually pound metal
apart.  They do not interact = linearly as do "sound waves" - in fact they can
respond in what = at first=20 seems to be weird ways.  For instance they may
reverse there = "polarity" depending on whether they encounter an open or
closed=20 termination.

It has only been with the advent of digital = computers=20 has it been practical
to even try and model the effects of these = waves in=20 an induction system.  I
find them fascinating.

Here = are a few=20 references that some of you might find interesting.

http://h= ome.earthlink.net/~redcat/pulse_ram/theory.html

http://www.motionsoftw= are.com/simtech.htm

http://www.pr= oracingsim.com/dynomationmainpage.htm

http://www.audietech= .com/DMfeaturetable.htm


Ed=20 Anderson
Side intake port engines produce different tuned effects than = do=20 Periphery ported intake engines.
 
Side exhaust ported engines produce different tuned effects = than do=20 periphery ported exhaust engines.
 
The most powerfull engine would be the Periphery intake and = exhaust=20 ported engines.
 
Although the intake and exhaust open and close events are = reported in=20 degrees of crankshaft rotation
just like a side port engine, the periphery ports never = actually close.=20 So, tuned lengths produce bigger changes than in the side ported = engine. So,=20 one end of the tune length is virtually open all of the time, and = worse one=20 end is exposed to changeing pressures all of the time.
 
The overlap (Intake and exhaust open at the same time) is huge. = So=20 exhaust back pressure can poison the intake quite badly.
 
In the side intake ported engine one end of the column is = closed solid=20 by the side of the rotor. Intake and exhaust overlap may be minimal = or=20 extensive. Column lengths produce crisp tuning. Overlap with = peripheral=20 exhaust ports may have less effect. Exhaust back pressure can remove = much=20 power.
 
Side intake and exhaust Renesis) may have no overlap at all. = The center=20 exhaust ports share an exit that is too large right at the port = face. Even=20 with no overlap, the intake can be poisoned by exhaust gasses being = held in=20 the chamber by a poor exhaust system. Exhaust system has three=20 outlets
 
Possibly less sensitive to back pressure than other designs = When=20 converted to a Periphery intake port, may still have low overlap. =
 
Lynn E. Hanover.
 
 

 

Hotmail: Trusted email with powerful SPAM protection. Sign up = now.=20
The New Busy is not the old busy. Search, chat and e-mail from your = inbox. Get started. ------=_NextPart_000_000F_01CAD186.07B00740--