X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=G+5i7Os5 c=1 sm=1 tr=0 a=Zq0UDxBVaj+boCRZes9Bog==:117 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=J70Eh1EUuV4A:10 a=TwYdP5wkG_QA:10 a=r77TgQKjGQsHNAKrUKIA:9 a=pGLkceISAAAA:8 a=_EeEMxcBAAAA:8 a=Ia-xEzejAAAA:8 a=o1OHuDzbAAAA:8 a=_6GpL_ENAAAA:8 a=7g1VtSJxAAAA:8 a=hXVjmKtRab2v__3nNYkA:9 a=Ftw3zl9OOPDIYQsC:21 a=3eGCQHdmWp9VRmPx:21 a=pILNOxqGKmIA:10 a=Qa1je4BO31QA:10 a=5UeK9suJl1gA:10 a=gvSQh4r-fQ0A:10 a=4PR2P7QzAAAA:8 a=CTuuDAE1MzVeEYFVqD8A:9 a=_f2rboJzdE01TVAR:21 a=gwfg2aKre8dOexIq:21 a=cYc6MnpuJmIb2s-J:21 a=_W_S_7VecoQA:10 a=syqr5EOPB93U0NEwqYpB:22 a=Urk15JJjZg1Xo0ryW_k8:22 a=5YQ6H4ZxyGn-KoBYtt8s:22 a=grOzbf7U_OpcSX4AJOnl:22 a=4dqwQCo7Po2mVW515mGf:22 From: "Finn Lassen finn.lassen@verizon.net" Received: from sonic313-13.consmr.mail.bf2.yahoo.com ([74.6.133.123] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 12953925 for flyrotary@lancaironline.net; Fri, 13 Sep 2019 10:58:02 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.6.133.123; envelope-from=finn.lassen@verizon.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=verizon.net; s=a2048; t=1568386666; bh=TKqnxqE+OtdPsBMBRaLwgD/kFhiePlEgl5h0ofh0NHQ=; h=Subject:To:References:From:Date:In-Reply-To:From:Subject; b=pyEIbd6/MLEfpgleYjLyMrkA+SB2D8FY/OfzFnneJMSDaI17gq2B6oPl750YyvxU6u/4UlWnz9jeGMSK3E/l8RAHHED/EeHYMCXnmzdwwJxc/BEaBrvaa6czVKIv7t9deGittHZcnay05J1H4dlmZKAeHvZp7Xwy++a/WB5S012z4uMWwk9rwTH0L6EyAlEH70ywl3t7V+vfP6nqqdd//8aRI31U+vn9MP9cuQLtu8/Yi8/vwxWApG8ZDgOtDnKQJ8srvuuXyKwd3275NbI87z0qfIzKZ9C3Bisn+E3BAFhveZbGze17OXS3bVS8x/hi0h12zdEVh9R15zNINAzb0w== X-YMail-OSG: CVQkzA8VM1k7soOe_ZHf8eCHqhfulRAcyLo.QTJ4vM8U8_OqAhSKHOh_8UzGi5Z _N2nm4IYkZsemXrKn8fGFjpSUeOT2auvv9iubQf3GVRDMzo98KBDPuDYTpThNpNpLONA0Hsp07Kw Y7XATPND35AsRLY8JlQrxzSoTmid4dYVEWjzV.ROgmpH4rbEHrFEZ7hENHb7d9YzjhIuSHrylsLk N6LN7RG8OKwjlnJ3eY6IDD4iVTs4MDuwVxwp0Fq1sVTPrhpV2WTD1cZex1ph4ijHKnluP1IIxN9z oQ5rGKW5hs0lduMY0hfx2np85MeUCAFjEN7D_aADpIx5j5XPCtlDol8b83l2nVcrqSN4lvHy9IKA T0gGJe8dpQVjTqSAaFfoKCca6bXYbPdf6mXQJAZzE554DjJh9BsA54qYOpmMk9pAvjCEt7PRaAxI Rwr396Ikoq8jaMr4uxAh4RIfLSuSxJftaxWGQJYFuecfK7cbDvZkWkYwW5GNOIJD71URttiP8jQ. qY3Yx.uBJ0zwkGg3z2X9CVQCuRAxctEJgzXtWjtMRTV6jnORD_regWIDbCHT_fzJmfeCY3sUX5I1 SKNvglOF7oaf5AejzEiePHTRqG6RK1TZTsrE3VqAYsIL.AM_Ynctir.cu.KymlE8YK13eSAB60aj osPUr6QzKThNQR0CJ1oCvY.JihRckeMzSj4ZaIXSI2ghdonTShBYdlEy_5kUCJoIgQzyk9z5BdyZ iOIkU6VSiWzYcPehOqK2MdVLpY_ViIboxb6uIc9OIPlxuefMNCDaJL18AbE2K6gufH3mdWszJwLQ SfG0F4x8cWONUXfG8W848ab2x7Osa2zD8rhXeQ.HGp6k89Fsp0d485gE8q0kADBahCT6QvMdkUoh 4_LtYcmcjyJcv4MNFsjU_p9QewP7t9y42ne4UMC.Srtxqt4NQk_j.Zm7pg6C7MjpQ.KElAMzhl_E YabxjthHySw4yVO9XRuk92wxRkoK3zbNzPbwNyWPxzk2_i5quZpGbOjrS.RrCvHoV_Nw0xCyilA3 RbTVoDLQzVsX5QQKMuSd7FIZxZvNs2Wfh_o7O2sqSYLb8yewLKiicq0il7c_oMvfsd5nR79ocmlx h3jX9pwNg5ISu3bBuXfrH56sUuvyABhNLW0EM9vuXiVmGlx97bFJ0NhJHIoHV2iR53XwyWFuNoTt g.uL7HQmKV9Jym0DrSO5g.yTAVREuOnccKZ_H0lm1IOvGJc_LzqEVXboRb8f.6M3AQaAGFAWT2SQ 9NXSJeUgUP4Ak4jy1sR8MUyVh6qlUt2URTpMoUejbbP9tVsQQNyMvwLwufDMp Received: from sonic.gate.mail.ne1.yahoo.com by sonic313.consmr.mail.bf2.yahoo.com with HTTP; Fri, 13 Sep 2019 14:57:46 +0000 Received: by smtp406.mail.bf1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID e18138e192754e052b54b9abd6ee9b1f; Fri, 13 Sep 2019 14:57:42 +0000 (UTC) Subject: Re: [FlyRotary] Re: Intake progress To: Rotary motors in aircraft References: Message-ID: Date: Fri, 13 Sep 2019 10:57:39 -0400 User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/alternative; boundary="------------DF19FDAAFA4A928D70A5562B" Content-Language: en-US This is a multi-part message in MIME format. --------------DF19FDAAFA4A928D70A5562B Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit So, given four 12" 1.25" OD runners the plenum only needs to be 4 x 12 x (1.25/2)^2 * Pi = 94 cu in ? So 3x4x12 = 144 cu in (inside) should be plenty? (allowing for the space that runners and bell mouths take up in the plenum) Or does it need to be exact for the plenum to be a Helmholtz resonator? Finn On 9/12/2019 10:47 PM, Le Roux Breytenbach breytenbachleroux@gmail.com wrote: > Charlie: I designed my intake plenum out of 125 mm (5 inch) irrigation > pipe as a mould and covered it (rolled) it with 8 layers of > bidirectional glass cloth. > The end cap on intake side for the throttlebody is 8 mm fenolic sheet > that is covered with glass cloth to use as a hard point to bolt the TB > (throttlebody)The other end cap is roundshaped to optimize waves > "bouncing" inside the plenum. > The total volume of the intake runners from the rotary surface to the > bell mouths must be calculated. > The volume of the intake plenum must be 2,5 x intake volume if the > intake runners. > I has p ported my 13B with 2 x 45 mm inside diameter runners. > For the best VE ( volumetric efficiency) the "proof is in the poeding > " to tunned the length of the intake runners. > Don't know your setup , but for p port 13B it is somewhere between 21 > and 24 inch intake runners. > Has build the plenum so that it can bolt open to work and inspections > inside. > I have build my own intake bell mouth velocity stacks and covered it > with carbon fiber braided sleaves. > The whole plenum box can be slide "up and down" on the runners to > tunned it on run ups for final testing for VE > Still building and no testing has been done at this stage > Will post some photos for comments, has to crop them on pc before > mailing for size tomorrow morning > > As Lynn always say "I could be wrong" > > Le Roux > > > Get Outlook for iOS > ------------------------------------------------------------------------ > *From:* Rotary motors in aircraft on > behalf of Charlie England ceengland7@gmail.com > > *Sent:* Friday, September 13, 2019 3:20 AM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Intake progress > My '1st draft' (before the box) was a 6 " aluminum tube (irrigation > tubing) that I re-contoured into a wavy contraption a little closer to > flat where the bellmouths faced. 1/4" aluminum plate for the ends. That > looked questionable, so I went worse. :-(?? I would expect a round tube > with 1/4" end plates to handle the loads, but I haven't proven it. > > On intake size, most of the stuff I've read addressing both induction > air and cooling talks about taking in every bit of the air needed and no > more, because trying to take in more than needed either adds drag as the > extra air flows through the plane's systems, or adds drag due to > spillage & turbulence around the lips of the intake. Achieving that goal > is a pretty high bar, though, given the wide speed variations of fast > a/c. Bernie Kerr (Hi Bernie, are you still watching?) used to talk about > 'external diffusion' (as opposed to internal diffusion, where the air > enters the duct at system airspeed and slows within the duct), which > apparently works well by slowing the air in front of the duct and > minimizes spillage losses by optimizing the lip of the entrance. > Apparently has the additional advantage of making duct shape less > critical. > > You can calculate the volume of air the engine ingests per second, then > calculate the intake size required to take in that volume of air per > second, all at expected operational speed. I suspect that's what Tracy > did. I chose the easy (lazy) way out & sized the inlet the same as? the > throttle body/total intake tube area, and am willing to accept 'external > diffusion' spillage at speed. > > Or, like Lynn often says, I could be wrong. :-) > > Charlie > > On 9/12/2019 5:47 PM, Finn Lassen finn.lassen@verizon.net wrote: > > Thanks Charlie, > > > > I was planning on using 1/4" plywood wrapped in fiberglass. (Tracy had > > warned me.) I do have a length of 6" OD 0.035 SS pipe, but what about > > the ends (or end opposite throttle body)? > > I can weld SS with my Henrob, but no success with aluminum. Also the > > curve of the pipe would make me shorten the intake runners a bit to > > make room around the bell mouths. > > > > I started reading the grapeape-inductionsystems.pdf paper and realized > > that's going to take quite a bit of study and research. Like what is > > the VE (Volumetric Efficiency) of a Renesis? > > > > Seems I start with the best intentions to design the optimal > > installation and end up copping out and doing "looks about right" or > > "what he did". > > > > Like, I have no clue how big my air intake opening should be. Just the > > size of the throttle body? Tracy mentioned something about the air > > intake should gradually open up to the size of the throttle body. I > > should now have plenty of room in the left cheek for a straight run > > from near the prop to the throttle body mounted on the plenum (shoe > box). > > > > Finn > > > > On 9/12/2019 5:26 PM, Charlie England ceengland7@gmail.com wrote: > >> Like most people's dad used to say, "Don't do as I do (did); do as I > >> say." :-) > >> > >> Tracy looked at my box after it was built & pointed out what I should > >> have considered: those big flat (thin) aluminum panels won't survive > >> intake pressure waves. I knew better, but that part of my mind had > >> gone on break during the entire construction of the box. Car makers > >> don't waste aluminum making cast 1/4" thick plenums just to get rid > >> of surplus aluminum. :-) > >> > >> That box is now lined with 1/4" plywood and fiberglass, and weighs > >> far too much. I'm doubtful that it will be a flight item. > >> > >> I'd suggest doing what Tracy did, & start with plywood/fiberglass, or > >> use a 4"-6" round aluminum tube for the plenum. I can probably dig up > >> some 6" if you want to try it, or check local farm-market > >> publications down there for surplus irrigation pipe. > >> > >> I never did find any tube length/plenum sizing advice for the rotary > >> that I trusted. Very few Renesis car guys ever touch the stock > >> manifold, since it would be very difficult to improve on Mazda's > >> design for a car. > >> > >> Charlie > >> > >> On 9/12/2019 12:02 PM, Finn Lassen finn.lassen@verizon.net wrote: > >>> 6 1/2 years later I'm about to do the same and would like to ask the > >>> same question before I make my "shoe box": > >>> > >>> "I'm curious about how others have adapted the common Helmholtz > >>> intake tuning formulas to the rotary. Would anyone care to 'show > >>> their (math) work'?" > >>> > >>> Rather than building it as big as possible, I'd like to know if > >>> there is an optimal size. > >>> > >>> Finn > >>> > >>> Charlie's photo: > >>> > >>> > >>> > >>> On 2/17/2013 3:41 PM, Charlie England wrote: > >>>> > >>>> Now that everyone's awake again, I thought I'd send a pic of my > >>>> intake progress (RV-7 Renesis with James Lyc cowl). I played with a > >>>> couple of different materials for the bell mouths. I tried gluing > >>>> up some 1/4" plexi from an old windshield, but used super glue > >>>> instead of proper plexi cement (which I wasn't able to find locally > >>>> in a hurry). The 1st try popped apart on the lathe; the 2nd turned > >>>> out ok. Next effort was with 3/4" MDF (medium density fiberboard). > >>>> That went well, until I put a little too much side pressure on the > >>>> ring (homemade cutting tool) after undercutting the center section. > >>>> Overall tube lengths will be ~11 3/4" block surface to bell ends. > >>>> The plenum is *much* bigger than most tuning sites recommend. I > >>>> figure that I can experiment with plenum size by just stuffing it > >>>> with rigid foam to take up some volume, if needed. Going the other > >>>> way wouldn't be so easy. :-) > >>>> > >>>> Since I don't have Mark's TIG skills, I thought I'd ask what others > >>>> have used in joining thin wall tubing to 1/4" aluminum plate. > >>>> Aluminum brazing rod? High temp epoxy? JB weld? I do intend to add > >>>> bracing from the plate to the plenum assembly to take some of the > >>>> cantilever & vibration stress off the tubes. > >>>> > >>>> I'm using this length and concept because Tracy has had great luck > >>>> with both HP & BSFC on his Renesis with a similar configuration. > >>>> However, I'm curious about how others have adapted the common > >>>> Helmholtz intake tuning formulas to the rotary. Would anyone care > >>>> to 'show their (math) work'? Renesis users would be better for me, > >>>> but any calcs would do. When I tried to adapt the common formulas > >>>> to a rotary, I was getting 'interesting' results, so I'd like to > >>>> know if I got lost somewhere while trying to plug rotary 'valve' > >>>> timing into the formulas. > >>>> > >>>> Charlie > >>>> (Sorry for the sideways iphone pic; I guess you can pretend that > >>>> you're looking down on it...) > >>> > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html --------------DF19FDAAFA4A928D70A5562B Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 8bit
So, given four 12" 1.25" OD runners the plenum only needs to be 4 x 12 x (1.25/2)^2 * Pi = 94 cu in ?

So 3x4x12 = 144 cu in (inside) should be plenty?
(allowing for the space that runners and bell mouths take up in the plenum)

Or does it need to be exact for the plenum to be a Helmholtz resonator?

Finn

On 9/12/2019 10:47 PM, Le Roux Breytenbach breytenbachleroux@gmail.com wrote:
Charlie: I designed my intake plenum out of 125 mm (5 inch) irrigation pipe as a mould and covered it (rolled) it with 8 layers of bidirectional glass cloth.
The end cap on intake side for the throttlebody is 8 mm fenolic sheet that is covered with glass cloth to use as a hard point to bolt the TB (throttlebody)The other end cap is roundshaped to optimize waves "bouncing" inside the plenum.
The total volume of the intake runners from the rotary surface to the bell mouths must be calculated.
The volume of the intake plenum must be 2,5 x intake volume if the intake runners.
I has p ported my 13B with 2 x 45 mm inside diameter runners.
For the best VE ( volumetric efficiency) the "proof is in the poeding " to tunned the length of the intake runners.
Don't know your setup , but for p port 13B it is somewhere between 21 and 24 inch intake runners.
Has build the plenum so that it can bolt open to work and inspections inside.
I have build my own intake bell mouth velocity stacks and covered it with carbon fiber braided sleaves.
The whole plenum box can be slide "up and down" on the runners to tunned it on run ups for final testing for VE
Still building and no testing has been done at this stage
Will post some photos for comments, has to crop them on pc before mailing for size tomorrow morning

As Lynn always say "I could be wrong"

Le Roux


Get Outlook for iOS
?
From: Rotary motors in aircraft <flyrotary@lancaironline.net> on behalf of Charlie England ceengland7@gmail.com <flyrotary@lancaironline.net>
Sent: Friday, September 13, 2019 3:20 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Intake progress
?
My '1st draft' (before the box) was a 6 " aluminum tube (irrigation
tubing) that I re-contoured into a wavy contraption a little closer to
flat where the bellmouths faced. 1/4" aluminum plate for the ends. That
looked questionable, so I went worse. :-(?? I would expect a round tube
with 1/4" end plates to handle the loads, but I haven't proven it.

On intake size, most of the stuff I've read addressing both induction
air and cooling talks about taking in every bit of the air needed and no
more, because trying to take in more than needed either adds drag as the
extra air flows through the plane's systems, or adds drag due to
spillage & turbulence around the lips of the intake. Achieving that goal
is a pretty high bar, though, given the wide speed variations of fast
a/c. Bernie Kerr (Hi Bernie, are you still watching?) used to talk about
'external diffusion' (as opposed to internal diffusion, where the air
enters the duct at system airspeed and slows within the duct), which
apparently works well by slowing the air in front of the duct and
minimizes spillage losses by optimizing the lip of the entrance.
Apparently has the additional advantage of making duct shape less critical.

You can calculate the volume of air the engine ingests per second, then
calculate the intake size required to take in that volume of air per
second, all at expected operational speed. I suspect that's what Tracy
did. I chose the easy (lazy) way out & sized the inlet the same as? the
throttle body/total intake tube area, and am willing to accept 'external
diffusion' spillage at speed.

Or, like Lynn often says, I could be wrong. :-)

Charlie

On 9/12/2019 5:47 PM, Finn Lassen finn.lassen@verizon.net wrote:
> Thanks Charlie,
>
> I was planning on using 1/4" plywood wrapped in fiberglass. (Tracy had
> warned me.) I do have a length of 6" OD 0.035 SS pipe, but what about
> the ends (or end opposite throttle body)?
> I can weld SS with my Henrob, but no success with aluminum. Also the
> curve of the pipe would make me shorten the intake runners a bit to
> make room around the bell mouths.
>
> I started reading the grapeape-inductionsystems.pdf paper and realized
> that's going to take quite a bit of study and research. Like what is
> the VE (Volumetric Efficiency) of a Renesis?
>
> Seems I start with the best intentions to design the optimal
> installation and end up copping out and doing "looks about right" or
> "what he did".
>
> Like, I have no clue how big my air intake opening should be. Just the
> size of the throttle body? Tracy mentioned something about the air
> intake should gradually open up to the size of the throttle body. I
> should now have plenty of room in the left cheek for a straight run
> from near the prop to the throttle body mounted on the plenum (shoe box).
>
> Finn
>
> On 9/12/2019 5:26 PM, Charlie England ceengland7@gmail.com wrote:
>> Like most people's dad used to say, "Don't do as I do (did); do as I
>> say." :-)
>>
>> Tracy looked at my box after it was built & pointed out what I should
>> have considered: those big flat (thin) aluminum panels won't survive
>> intake pressure waves. I knew better, but that part of my mind had
>> gone on break during the entire construction of the box. Car makers
>> don't waste aluminum making cast 1/4" thick plenums just to get rid
>> of surplus aluminum. :-)
>>
>> That box is now lined with 1/4" plywood and fiberglass, and weighs
>> far too much. I'm doubtful that it will be a flight item.
>>
>> I'd suggest doing what Tracy did, & start with plywood/fiberglass, or
>> use a 4"-6" round aluminum tube for the plenum. I can probably dig up
>> some 6" if you want to try it, or check local farm-market
>> publications down there for surplus irrigation pipe.
>>
>> I never did find any tube length/plenum sizing advice for the rotary
>> that I trusted. Very few Renesis car guys ever touch the stock
>> manifold, since it would be very difficult to improve on Mazda's
>> design for a car.
>>
>> Charlie
>>
>> On 9/12/2019 12:02 PM, Finn Lassen finn.lassen@verizon.net wrote:
>>> 6 1/2 years later I'm about to do the same and would like to ask the
>>> same question before I make my "shoe box":
>>>
>>> "I'm curious about how others have adapted the common Helmholtz
>>> intake tuning formulas to the rotary. Would anyone care to 'show
>>> their (math) work'?"
>>>
>>> Rather than building it as big as possible, I'd like to know if
>>> there is an optimal size.
>>>
>>> Finn
>>>
>>> Charlie's photo:
>>>
>>>
>>>
>>> On 2/17/2013 3:41 PM, Charlie England wrote:
>>>>
>>>> Now that everyone's awake again, I thought I'd send a pic of my
>>>> intake progress (RV-7 Renesis with James Lyc cowl). I played with a
>>>> couple of different materials for the bell mouths. I tried gluing
>>>> up some 1/4" plexi from an old windshield, but used super glue
>>>> instead of proper plexi cement (which I wasn't able to find locally
>>>> in a hurry). The 1st try popped apart on the lathe; the 2nd turned
>>>> out ok. Next effort was with 3/4" MDF (medium density fiberboard).
>>>> That went well, until I put a little too much side pressure on the
>>>> ring (homemade cutting tool) after undercutting the center section.
>>>> Overall tube lengths will be ~11 3/4" block surface to bell ends.
>>>> The plenum is *much* bigger than most tuning sites recommend. I
>>>> figure that I can experiment with plenum size by just stuffing it
>>>> with rigid foam to take up some volume, if needed. Going the other
>>>> way wouldn't be so easy. :-)
>>>>
>>>> Since I don't have Mark's TIG skills, I thought I'd ask what others
>>>> have used in joining thin wall tubing to 1/4" aluminum plate.
>>>> Aluminum brazing rod? High temp epoxy? JB weld? I do intend to add
>>>> bracing from the plate to the plenum assembly to take some of the
>>>> cantilever & vibration stress off the tubes.
>>>>
>>>> I'm using this length and concept because Tracy has had great luck
>>>> with both HP & BSFC on his Renesis with a similar configuration.
>>>> However, I'm curious about how others have adapted the common
>>>> Helmholtz intake tuning formulas to the rotary. Would anyone care
>>>> to 'show their (math) work'? Renesis users would be better for me,
>>>> but any calcs would do. When I tried to adapt the common formulas
>>>> to a rotary, I was getting 'interesting' results, so I'd like to
>>>> know if I got lost somewhere while trying to plug rotary 'valve'
>>>> timing into the formulas.
>>>>
>>>> Charlie
>>>> (Sorry for the sideways iphone pic; I guess you can pretend that
>>>> you're looking down on it...)
>>>


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