X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.122] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4551795 for flyrotary@lancaironline.net; Tue, 02 Nov 2010 08:01:50 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.122; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=3jtQBdTzPyV+fq4oCU/u8ZPrJJGN11HvhaDVxyWhycI= c=1 sm=0 a=-8-kWA4LOUgA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=fN7KZKRRAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=cm0aX8SmRPBIEapzGicA:9 a=U01N2eTiBslElwSsyfsA:7 a=pK-uuornJ3fvvfVevO_OT8D4DV4A:4 a=wPNLvfGTeEIA:10 a=NVEn_trjWQeZAwy0:21 a=A8D9PM1YZMm18LS_:21 a=Ia-xEzejAAAA:8 a=ayC55rCoAAAA:8 a=TMUFuW__qCtun5n7o9AA:9 a=gUgJq2joOALoe3Wk3tcA:7 a=1LclcAT3qEGwHC3BHkok6ZYJzJgA:4 a=EzXvWhQp4_cA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:53579] helo=EdPC) by cdptpa-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 86/79-02631-98DFFCC4; Tue, 02 Nov 2010 12:01:14 +0000 Message-ID: <3D0696F03624453E89775A625B2F269F@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Fw: LeMann's Induction system II Re: EM2 Numbers Date: Tue, 2 Nov 2010 08:01:05 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001F_01CB7A64.19B39970" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_001F_01CB7A64.19B39970 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ok, Steve, I see your point. Ed From: stevei@carey.asn.au=20 Sent: Tuesday, November 02, 2010 7:33 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Fw: LeMann's Induction system II Re: EM2 = Numbers Hi Ed=20 I realise that a total length was being sought. However, I was observing = the change in length and how that effected the peak torque. So if you = want to lift the peak torque approx 1000RPM in the 5500 to 6500 band on = a system similar to the 26B intake tube dimensions, it seems that 2" = would be about right. Steve On 01/11/2010, at 11:15 PM, Ed Anderson wrote: From: Ed Anderson=20 Sent: Monday, November 01, 2010 11:04 AM To: Rotary motors in aircraft=20 Subject: LeMann's Induction system II Re: EM2 Numbers Hi Steve, Thanks for the graph, in reading up on the R26B LeMann engine (yes, I = finally located the SAE paper on the web) - the length in the graph = appears to refer ONLY the change in length of telescoping portion of the = variable induction on the LeManns. You can see from the photo graphs = that fully extended the total induction length is over twice the maximum = 175mm of the telescoping length. =20 Also this assertion is supported by this quote from the Mazda SAE = paper on the R26b engine The TIMS pipe can slide a maximum of 175 mm. =20 The paper can be found at: http://www.rotaryeng.net/Mazda_R26B_US.pdf So if the telescoping portion can slide a maximum of 175mm then the = total induction system is clearly longer as can be seen in the sketch of = the engine below. Therefore if making calculations its crucial to understand that this = 175MM appears to be ONLY the max length of the telescoping portion of = the total induction length and not the total length. Makes a big = difference! =20 =20 =20 =20 In this photo you can see the telescoping section extended to its full = length. I have attached a larger scale drawing of the total induction system = for those who want to make their own determination of the intake length. = If the telescoping portion is fully extended then it appears that the = rest of the length is approx 1.75 the length of the telescoping section = as best as I could determine by relative scaling.=20 Example Calculation I measured the diameter of the rotor housing (smallest dimension) and = found it to be 7 1/8". I then took a circle and made it the same = diameter and then used that from one end of the extended intake to the = combustion chamber entrance and came up with 3.5 diameters or 3.5 * = 7.125 =3D 24.9 inches or say 25inches. That figure does not appear = unreasonable just looking at the relative length of the extended tube = length in the photo. So if the telescoping section is fully extended at 6000 rpm then the = total induction length is approx 25 inches. =20 if 25 inches then a pulse generated by the opening of the intake port = traveling to the entrance of the intake and reflected back to the intake = port (to aid in stuffing the combustion chamber) would need to travel = twice that distance or 50 inches. 50 inches is 4.167 ft which = traveling at the velocity of sound at sea level of 1100 ft/sec would = need 41.6/ 1100 =3D 0.00378 seconds to make the round trip. Assuming = the pulse is generated by the opening of the intake port which causes = the trapped remant exhaust gas to burst forth into the intake thereby = generating a shockwave/pulse and you want it to arrive back as the port = is closing. Here are the PP port timings as found on Paul Yaws excellent web site = on the rotary engine.=20 Mazda Factory Peripheral Port IO 86=B0 BTDC IC 75=B0 ABDC EO 73=B0 BBDC EC 65=B0 ATDC=20 This site is meant to give information=20 Don't know if this is the port opening on the R26B engine but the only = thing I could find. So 86 BTDC opening (pulse goes out) and 75 ABDC (Pulse arrives back), = so total rotation from opening to closing is 86 + 75 =3D 181 deg, now it = will be somewhat less than this as it takes some finite time for the = pulse to be fully generated and you want it to arrive back probably = 15-20 deg before the port closes. But for the moment lets ignore those realities and see what we get. So 180 / 0.00378 =3D 47520 deg/sec of rotation speed required. 47520 = /360 =3D 132 revs/sec *60 =3D 7920 rpm which is a bit high.=20 If we now adjust from some realities such as time it takes to = generate the pulse and having it arrive back before closing. Somewhere = I found some data in an engine book that indicates it would probably = take around 5-10 % of open time to generate the pulse peak. So taking = 7.5 % opening time =3D 13.75 deg, so taking 14 Deg that and lets say 15 = % of total open period arrival before port closes. 0.20 * 181 =3D 27.2 = deg before closing, we have 181 - (14+27.2) =3D 139.9 deg total = rotation travel time for the pulse to transverse the intake. 140/0.00378 =3D 36960 deg/sec rotation speed required. 36960/360 =3D = 103 rev/sec * 60 sec =3D 6180 rpm - not too far from 6000 rpm. A few = deg error in assumption of the time it takes to generate the pulse and = the time its suppose to arrive back at the port could easily account for = the difference. So if my estimates of the time it takes to generate the pulse and = when the pulse arrives back are off then naturally the calculation will = be off as well. My point is that Mark is correct - the length of the induction systems = (and exhaust system) has a significant effect - probably more so for the = PP than the normal ported 13B. At the other end of the telescopic length =3D 0 leaves approx 27 - = 6.88 =3D say 20 inches of total induction length. With the same assumptions for the pulse - we have travel time for 20 = inches induction length =3D 40 inches for the round trip. 40/12 =3D = 3.33 ft. 3.33/1100 =3D 0.00303 travel time. 140/0.0303 =3D 46200 deg /sec rotation speed required. 45200/360 =3D = 128.3 revs/sec * 60 sec =3D 7700 rpm. A bit low compared to the chart = below - that could be because the pulse generation time and the pulse = closing target may not change linearly with higher rpm.=20 But again, my point is that length does matter (no matter what the = lady said {:>) Back to my cave Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com From: stevei@carey.asn.au=20 Sent: Monday, November 01, 2010 5:09 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: EM2 Numbers Hi Mark=20 I have attached the Leman intake dimensions from Paul L. Hope this is helpful. Can't remember whether this measurement was to = the rotor face or manifold face. Steve Izett Perth Western Australia=20 =20 -------------------------------------------------------------------------= ----- The contents of this email are confidential and intended only for the = named recipients of this e-mail. If you have received this e-mail in = error, you are hereby notified that any use, reproduction, disclosure or = distribution or the information contained in this e-mail is prohibited. = Please notify the sender immediately and then delete/destroy the e-mail = and any printed copies. All liability for viruses is excluded to the = fullest extent of the law. ------=_NextPart_000_001F_01CB7A64.19B39970 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ok, Steve, I see your point.
 
Ed

Sent: Tuesday, November 02, 2010 7:33 AM
Subject: [FlyRotary] Re: Fw: LeMann's Induction system II = Re: EM2=20 Numbers

Hi Ed=20

I realise that a total length was being sought. However, I was = observing=20 the change in length and how that effected the peak torque. So if you = want to=20 lift the peak torque approx 1000RPM in the 5500 to 6500 band on a system = similar=20 to the 26B intake tube dimensions, it seems that 2" would be about = right.

Steve

On 01/11/2010, at 11:15 PM, Ed Anderson wrote:
 

Sent: Monday, November 01, 2010 11:04 AM
To: Rotary motors in = aircraft
Subject: LeMann's Induction system II Re: EM2=20 Numbers

Hi Steve,
 
Thanks for the graph, in reading up on the R26B LeMann=20 engine (yes, I finally located the SAE paper on the web)  - = the=20 length in the graph appears to refer ONLY the change in length of=20 telescoping portion of the variable induction on the=20 LeManns.  You can see from the photo graphs that fully extended = the total=20 induction length is over twice the maximum 175mm of the telescoping=20 length. 
 
Also this assertion is supported by this quote from the Mazda SAE = paper=20 on the R26b engine
 

The TIMS pipe can slide a = maximum of=20 175 mm. 

The paper can be found = at:

http://www.rotaryeng.= net/Mazda_R26B_US.pdf

So if the = telescoping portion can=20 slide a maximum of 175mm then the total induction system is clearly = longer as=20 can be seen in the sketch of the engine=20 = below.

<= /DIV>
Therefore if making calculations its crucial to = understand that=20 this 175MM  appears to be ONLY the max length of the = telescoping=20 portion of the total induction length and not the total length.  = Makes a=20 big difference!
 
 
<B4C1.jpg>
<B4D1.jpg>
 
 
In this photo you can see the telescoping section = extended to its=20 full length.
 
I have attached a larger scale drawing of the total = induction=20 system for those who want to make their own determination of the = intake=20 length.  If the telescoping portion is fully extended then = it=20 appears that the rest of the length is approx 1.75 the length of the=20 telescoping section as best as I could determine by relative=20 scaling. 
 
Example=20 Calculation
 
 
I measured the diameter of the rotor housing (smallest = dimension)=20 and found it to be 7 1/8".  I then took a circle and made it the = same=20 diameter and then used that from one end of the extended  intake = to the=20 combustion chamber entrance and came up with 3.5 diameters or 3.5 = * 7.125=20 =3D  24.9 inches or say 25inches. That figure does not appear = unreasonable=20 just looking at the relative length of the extended tube length in the = photo.
 
So if the telescoping section is fully extended at 6000 = rpm then=20 the total induction length is approx  25  inches. =20
 
if 25 inches then a pulse generated by the opening of the = intake=20 port traveling to the entrance of the intake and reflected back to the = intake=20 port (to aid in stuffing the combustion chamber) would need to travel = twice=20 that distance or 50 inches.  50  inches is 4.167 ft = which=20 traveling at the velocity of sound at sea level of 1100 ft/sec would = need=20 41.6/ 1100 =3D 0.00378 seconds to make the round trip.  Assuming = the pulse=20 is generated by the opening of the intake port which causes the = trapped remant=20 exhaust gas to burst forth into the intake thereby generating a=20 shockwave/pulse and you want it to arrive back as the port is=20 closing.
 
 Here=20 are the PP port timings as found on Paul Yaws excellent web site on = the rotary=20 engine.=20

Mazda Factory Peripheral Port

IO 86=B0 BTDC
IC 75=B0 ABDC
EO 73=B0 BBDC
EC 65=B0 ATDC =

This site is meant to give information =
Don't know if this is the port opening on the R26B engine = but the=20 only thing I could find.
 
So 86 BTDC opening (pulse goes out) and 75 ABDC (Pulse = arrives=20 back), so total rotation from opening to closing is 86 + 75 =3D 181 = deg, now it=20 will be somewhat less than this as it takes some finite time for the = pulse to=20 be fully generated and you want it to arrive back probably 15-20 deg = before=20 the port closes.
 
But for the moment lets ignore those realities and see what we = get.
 
So 180 / 0.00378 =3D 47520 deg/sec of rotation = speed=20 required.  47520 /360 =3D 132 revs/sec *60 =3D 7920 rpm = which is a bit=20 high. 
 
 If we now adjust from some realities such as time = it takes to=20 generate the pulse and having it arrive back before closing.  = Somewhere I=20 found some data in an engine book that indicates it would probably = take=20 around 5-10 % of open time to generate the pulse peak.  So = taking=20 7.5 % opening time =3D 13.75 deg, so taking 14 Deg that and lets = say 15 %=20 of total open period arrival before port = closes.  0.20 *=20 181 =3D 27.2 deg before closing,  we have 181 = - (14+27.2)=20  =3D 139.9  deg total rotation travel time for the = pulse to=20 transverse the intake.
 
140/0.00378  =3D 36960 deg/sec rotation = speed=20 required.  36960/360 =3D 103 rev/sec * 60 sec =3D 6180 rpm - not = too far from=20 6000 rpm.  A few deg error in assumption of the time it takes to = generate=20 the pulse and the time its suppose to arrive back at the port could = easily=20 account for the difference.
 
So  if my estimates of the time it takes to = generate=20 the pulse and when the pulse arrives back are off then naturally the=20 calculation will be off as well.
 
My point is that Mark is correct - the length = of the=20 induction systems (and exhaust system) has a significant effect - = probably=20 more so for the PP than the normal ported 13B.
 
At the other end of the telescopic length =3D = 0 leaves=20 approx 27 - 6.88 =3D say 20 inches of total induction = length.
 
With the same assumptions for the pulse  = - we have=20 travel time for 20 inches induction length =3D 40 inches for the round = trip.  40/12 =3D 3.33 ft.  3.33/1100 =3D 0.00303 travel=20 time.
 
140/0.0303 =3D 46200 deg /sec rotation speed=20 required.  45200/360 =3D 128.3 revs/sec * 60 sec =3D 7700 = rpm.  A bit=20 low compared to the chart  below - that could be because the = pulse=20 generation time and the pulse closing target may not change linearly = with=20 higher rpm.
 
But again, my point is that length = does matter=20 (no matter what the lady said {:>)
 
Back to my cave
 
Ed
 
Edward = L.=20 Anderson
Anderson Electronic Enterprises LLC
305 Reefton=20 Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

From: stevei@carey.asn.au
Sent: Monday, November 01, 2010 5:09 AM
Subject: [FlyRotary] Re: EM2 Numbers

Hi Mark=20

I have attached the Leman intake dimensions from Paul L.
Hope this is helpful. Can't remember whether this measurement was = to the=20 rotor face or manifold face.

Steve Izett
Perth Western Australia 
<Lemans-torque-curves3.jpg>
  =20
The contents of this email = are confidential=20 and intended only for the named recipients of this e-mail. If you have = received this e-mail in error, you are hereby notified that any use,=20 reproduction, disclosure or distribution or the information contained = in this=20 e-mail is prohibited. Please notify the sender immediately and then=20 delete/destroy the e-mail and any printed copies. All liability for = viruses is=20 excluded to the fullest extent of the=20 = law.

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