X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.2 cv=cojZqBwi c=1 sm=1 tr=0 a=ECkzfDg7JJ+VnMwgUCA/Eg==:117 a=x7bEGLp0ZPQA:10 a=ocR9PWop10UA:10 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=UKPAHat8AAAA:8 a=7g1VtSJxAAAA:8 a=QqyL27jICRhO3OazjrQA:9 a=j2tCWluFgHbfiBaY:21 a=rs7TMMBIuStHp9uf:21 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=0ktnTxyZCdu9evxl7ZQA:9 a=QQhqq1E9Zmm7txcn:21 a=Rer7xYAqEOm86_L_:21 a=6nGpC5CHnR_3_-aZ:21 a=_W_S_7VecoQA:10 a=Urk15JJjZg1Xo0ryW_k8:22 a=Fc6xXSS-RxGHxrvp76Qp:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "Ernest Christley echristley@att.net" Received: from sonic311-25.consmr.mail.gq1.yahoo.com ([98.137.65.206] verified) by logan.com (CommuniGate Pro SMTP 6.2.0) with ESMTP id 10481771 for flyrotary@lancaironline.net; Thu, 28 Dec 2017 12:00:27 -0500 Received-SPF: none receiver=logan.com; client-ip=98.137.65.206; envelope-from=echristley@att.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=att.net; s=s1024; t=1514480393; bh=QeS0Es4iT7wRCCGzA7+3SormZbmtOunV963kdNc1ND0=; h=Date:From:Reply-To:To:In-Reply-To:References:Subject:From:Subject; b=gE7flDAlOn8/ELGHRwRlGM6CTv4z0qxOigPEBX7sC8GOu2Th0FnU7IbEtt0fUg9wXQKBmo3ft2po3HBm7jEHcMvrM0zdW3PACDI2hSiR/P4bzRSbEBzSTLzv4qn/kzrgNVRN1yJsNL3ATa2BEwS1g1wqCMnXgxXC4UeclulYnhA= X-YMail-OSG: Ni_L4F4VM1m2BXYrZdW3LX0x7QecBkk43xa0Gtcv1GBDy5z0DXCIo9GXfYvctNu Aim_0SAWWowBAmgwi9n99vrsXfAjCedWj1DR33clCYa7Oya4BvQpxET4UHRHSGi4_lxhvsj2PwoV mWSLUPHcxwD5z7DuXFuw4d0elcpD7KTYSjMVZZmg8xtALelKYwdHCl295WaC_8izG7pdTBTB2Hbp dz5Q_w659I0pi2y80iSq3lOAaD5grTLkoDnw3IuTldJtwKAuuwQG6ZwKOx3BSbOdxK.t.ztQGRGu xSLJpxnYmg2cW5YuVYULDQNIStXvBN.2eKE9kdSirpEK.nU.YFAPMfPmbWHCVbaQIW99HCEoF2X5 IzePW6fC.gdA4PeNkRXXRnZ6ruy8NKvUCTHJzgc3q.arJN3FfjLStvu6yRQ.tDr9ZP4rPxeLGk2X yKizxWgTMsWdne2QT7bn.QC2kFvhWVXs84NsTzaO5aWjAYtbV15Jvd0fefBJzxlGLd6a8_g2z5UL 3k18AYhxgqbw_Hm8- Received: from sonic.gate.mail.ne1.yahoo.com by sonic311.consmr.mail.gq1.yahoo.com with HTTP; Thu, 28 Dec 2017 16:59:53 +0000 Date: Thu, 28 Dec 2017 16:59:42 +0000 (UTC) Reply-To: Ernest Christley To: Rotary motors in aircraft Message-ID: <1948268650.4915066.1514480382462@mail.yahoo.com> In-Reply-To: References: Subject: Re: [FlyRotary] Re: cooling system troubeshooting MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_4915065_328638261.1514480382456" X-Mailer: WebService/1.1.11051 YahooMailNeo Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/604.4.7 (KHTML, like Gecko) Version/11.0.2 Safari/604.4.7 Content-Length: 25649 ------=_Part_4915065_328638261.1514480382456 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable One thing I discovered and fixed on the Delta I built is that for a radiato= r in the cowl, you need to pay close attention to how the exit air flows. = =C2=A0I discovered the problem when my manifold pressure tube melted. =C2= =A0In my setup, I had just one radiator mounted on the right side about 8" = in front of the firewall. =C2=A0Air would flow through the radiator, then s= lam against the firewall when it exited. =C2=A0Instead of flowing down and = out the bottom exit, the air set up a vortex and spun clockwise inside the = cowl. =C2=A0The air, after being heated by the exhaust, then blew up to mel= t the manifold pressure line. =C2=A0I installed a couple tin baffles from t= he bottom motor mount supports to the bottom of the cowl to break this vort= ex and direct the flow backwards and out the cowl exit. =C2=A0My water temp= s dropped 15 degrees on the next run.=20 On Thursday, December 28, 2017 9:07 AM, "Stephen Izett stephen.izett@gm= ail.com" wrote: =20 Hi Bobby With the top cowl off she cools a little better.=20 I put this down to air circulating/tumbling around the back of the radiator= . Cant remember what happened when we ran it a while back with the bottom cow= l off. Last week I did do some quick pressure tests and one troubled me. I had the differential pressure pickups in the cowl and water diffuser and = though the wool tufts say a small amount of air is flowing through the rad,= the pressure reading said it should be flowing backwards. This why I=E2=80=99m really keen to do the science and work out what the pr= essures are doing. Steve > On 28 Dec 2017, at 9:56 pm, Bobby J. Hughes bhughes@qnsi.net wrote: >=20 > Steve, >=20 > How does it cool with the cowling removed?=20 >=20 > Bobby >=20 > Sent from my iPad >=20 > On Dec 28, 2017, at 7:12 AM, Stephen Izett stephen.izett@gmail.com wrote: >=20 >> Hi Guys >> In search of cooler running this is what we did today and plan to do nex= t. >> Any insights/thoughts welcome. >>=20 >> Today we: >> 1. Installed a new pressurised tank with 21psi cap at the highest point = possible. It is fed from: >>=C2=A0 A. Rear Iron.=20 >>=C2=A0 B. Top of the coolant out manifold (engine heading for radiator).= =20 >>=C2=A0 C. Top of radiator inlet tank >> It returns to the pump inlet via a hose with a 1/8=E2=80=9D restriction. >> It overflows into an expansion tank accessible via a hatch in the top co= wl >>=20 >> 2. Tested new config: >> A. I wondered why she wasn=E2=80=99t running as sweet as usual and reali= sed the Leading plugs weren=E2=80=99t firing so fixed the problem. >> =C2=A0=C2=A0=C2=A0 With an OAT of ~ 80F after 20 mins of idle at 1800 rp= m water gets to over 225 and I shut it down. (No significant change from la= st setup) >> B. Measured Cowl pressure at a point between water radiator and cowl fla= p referenced to Static -=20 >> =C2=A0=C2=A0=C2=A0 At idle the pressure is 0 inches of water >> =C2=A0=C2=A0=C2=A0 At 6000rpm (fine pitch) it hits about negative 1/2 in= ch of water (the exit shape, exhaust augmenter and cowl flap appear to be p= roducing some negative pressure in the cowl) >> =C2=A0=C2=A0=C2=A0 I=E2=80=99ve currently stuffed the gear opening full = of pillows and rags to emulate the gear being up and door closed. >>=20 >> So here is the detail: >> The 193 inch^3 oil cooler is fed by a 7.4 inch^2 inlet well below the sp= inner and into a trumpet diffuser.=20 >> The 540 inch^3 water cooler is fed by the 16.5 inch^2 right cheek inlet = very close to the spinner and into a trumpet and then wedge diffuser. (Trie= d to copy Tracy=E2=80=99s RV8 cooler design) >> Ive put a matrix of wool tufts over the back of the water cooler and dis= tribution appears quite even. >> See photo showing oil cooler inlet below spinner vs cheeks. >> Currently the oil temps lag the water temps by a good 30F. >>=20 >> So next opportunity I=E2=80=99m thinking: >> 1. Because its a quick and easy test, I=E2=80=99m planning to close off = part of the oil cooler inlet and see what this does to the water temps. >> Will this provide a better balance between oil and water with the water = rad getting a better share of the exit air flow? >>=20 >> 2. Seek to plot a set of pressure measurements at various locations arou= nd the cowl and diffusers for various; >> 1. RPM=E2=80=99s >> 2. Cowl Flap position >> 3. Gear door open / closed (stuffed full of pillow and rag). >>=20 >> Many thanks for your ponderings and any of your thoughts. >>=20 >> Cheers >>=20 >> Steve >> Perth Western Australia >> Glasair Super IIRG - Renesis 4 port RD1C EC3 EM3=20 >>=20 >>=20 >>=20 >> =C2=A0=C2=A0=C2=A0 >>=C2=A0=20 >>> On 28 Dec 2017, at 7:37 am, Stephen Izett stephen.izett@gmail.com wrote: >>>=20 >>> Hi Steve >>>=20 >>> Aeroplane has not flown. We are still testing on the ground in OAT=E2= =80=99s of 80-100F >>> At idle (1900rpm) Delta T=E2=80=99s across Oil coiler - 18F, Water coil= er - 8F >>>=20 >>> We are seeking to do two things: >>> 1. Review our design - have we made a clear mistake somewhere - >>> a. We managed to not have an air bleed at the engine coolant in/out whi= ch is the highest point! >>> We only have returns to the pressurised expansion tank/cap from rear ir= on and one from the top of the radiator in tank (returning to pump in). >>> b. We do not have a small hole in the Renesis bypass which we plugged. >>> c. Lynn uses a restrictor in the outlet to make sure the pump isn=E2=80= =99t cavitating. Our coolant out plumbing has far less restriction than the= stock setup (All be it the radiator is a dual pass so presents=C2=A0 signi= ficantly more resistance) >>> d. We have just finished building a cowl flap in an attempt to control = cowl pressure. >>>=20 >>> 2. Do the science and seek to measure what the air and water are doing. >>> a. Not sure how to measure the water flow easily.=20 >>> b. We are testing today to see what air pressures exist around the diff= users and cowl. >>>=20 >>> Cheers >>>=20 >>> Steve >>>=20 >>>> On 28 Dec 2017, at 3:00 am, Steven W. Boese SBoese@uwyo.edu wrote: >>>>=20 >>>> Simply determining radiator coolant delta T may be useful in troublesh= ooting the cooling system.=C2=A0 The water cooling system is a closed syste= m with two heat exchangers: one is the engine putting heat into the coolant= and the other is the radiator removing heat from the coolant.=C2=A0 When a= ll of the coolant flows through the engine and radiator (coolant bypass pas= sage blocked by either a plug or a fully open thermostat) the engine and ra= diator must have the same coolant delta T.=C2=A0 At a given power level and= coolant flow rate we all should see similar delta T's since we are using v= ery similar engines.=C2=A0 At sea level full throttle, that coolant delta T= should be close to 15 degrees F.=C2=A0 Since the heat exchanger characteri= stics of a clean engine are essentially fixed, a coolant delta T of much mo= re than15 degrees F at full throttle would most likely be a result of insuf= ficient coolant flow rate through the system.=C2=A0 This could result from = a defective water pump or too much coolant bypassing the radiator such as d= ue to an incompletely closed thermostat bypass passage, too large air bleed= s from engine coolant high points, or an open cabin heater coolant loop.=C2= =A0 An EWP would introduce an additional variable.=C2=A0=20 >>>>=20 >>>> With proper coolant flow rate, when the radiator cannot remove enough = heat from the system, the overall coolant temperature will rise until one o= f two conditions are achieved.=C2=A0 First, the radiator may be capable of = removing enough heat with a greater delta T between the coolant and the air= .=C2=A0 The system will stabilize, but the delta T's of the coolant across = the engine and across the radiator will remain essentially equal and unchan= ged.=C2=A0 This type of behavior is demonstrated in the attached data plot = for a full throttle climb from 7,000 to 14,0000 ft msl with a typical OAT d= ecrease. >>>>=20 >>>> The second condition would be to boil the coolant and remove heat due = to the phase change.=C2=A0 This may not maintain a closed system and the st= able condition would then, of course, be temporary. >>>>=20 >>>> The goal of designing the radiator side of the cooling system is to si= ze the radiator and air flow through its core to achieve the desired overal= l coolant temperature.=C2=A0 Trying to change the coolant delta T at a give= n RPM and power level will prove frustrating. >>>>=20 >>>> The same would be true of the oil cooling system if the oil flow rate = was consistent between our systems.=C2=A0 However, if part of the oil flow = is returned to the sump at the front cover relief valve, comparisons betwee= n different setups will be of limited value unless the actual oil flow rate= s through the oil coolers are known.=C2=A0=20 >>>>=20 >>>> Steve Boese >>>> RV6A, 1986 13B NA, RD1A, EC2 >>>>=20 >>>>=20 >>>> -- >>>> Homepage:=C2=A0 http://www.flyrotary.com/ >>>> Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrot= ary/List.html >>>=20 >>>=20 >>> -- >>> Homepage:=C2=A0 http://www.flyrotary.com/ >>> Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrota= ry/List.html >>=20 -- Homepage:=C2=A0 http://www.flyrotary.com/ Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrotary/L= ist.html =20 ------=_Part_4915065_328638261.1514480382456 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
One thing I discovered and fixed on t= he Delta I built is that for a radiator in the cowl, you need to pay close = attention to how the exit air flows.  I discovered the problem when my= manifold pressure tube melted.  In my setup, I had just one radiator = mounted on the right side about 8" in front of the firewall.  Air woul= d flow through the radiator, then slam against the firewall when it exited.=  Instead of flowing down and out the bottom exit, the air set up a vo= rtex and spun clockwise inside the cowl.  The air, after being heated = by the exhaust, then blew up to melt the manifold pressure line.  I in= stalled a couple tin baffles from the bottom motor mount supports to the bo= ttom of the cowl to break this vortex and direct the flow backwards and out= the cowl exit.  My water temps dropped 15 degrees on the next run.


On Thursday, December 28, 2017 9:07 AM, "Stephen Izett stephen= .izett@gmail.com" <flyrotary@lancaironline.net> wrote:

Hi Bobby
With the top cowl off she cools a little better.
<= /div>
I put this down to air circulating/tumbling around th= e back of the radiator.
Cant remember what happen= ed when we ran it a while back with the bottom cowl off.

Last week I did do some quick pressure = tests and one troubled me.
I had the differential= pressure pickups in the cowl and water diffuser and though the wool tufts = say a small amount of air is flowing through the rad, the pressure reading = said it should be flowing backwards.
This why I= =E2=80=99m really keen to do the science and work out what the pressures ar= e doing.

Steve



> On 28 Dec 2017, at= 9:56 pm, Bobby J. Hughes bhughes@qnsi.net <flyrotar= y@lancaironline.net> wrote:
>
> Steve,
>
> How does it cool with the cowling removed?
>
> Bobby
>
> Sent from my iPad
>
> On Dec 28, 2017, at 7:1= 2 AM, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:
>
>> Hi Guys
>> In search of cooler running this is what we did today and plan = to do next.
>> Any insights/thoughts welcom= e.
>>
>> T= oday we:
>> 1. Installed a new pressurised = tank with 21psi cap at the highest point possible. It is fed from:
>>  A. Rear Iron.
&= gt;>  B. Top of the coolant out manifold (engine heading for radiat= or).
>>  C. Top of radiator inlet tan= k
>> It returns to the pump inlet via a hos= e with a 1/8=E2=80=9D restriction.
>> It ov= erflows into an expansion tank accessible via a hatch in the top cowl
>>
>> 2. Tested= new config:
>> A. I wondered why she wasn= =E2=80=99t running as sweet as usual and realised the Leading plugs weren= =E2=80=99t firing so fixed the problem.
>> =     With an OAT of ~ 80F after 20 mins of idle at 1800 rpm w= ater gets to over 225 and I shut it down. (No significant change from last = setup)
>> B. Measured Cowl pressure at a po= int between water radiator and cowl flap referenced to Static -
<= div dir=3D"ltr">>>     At idle the pressure is 0 inche= s of water
>>     At 6000rpm= (fine pitch) it hits about negative 1/2 inch of water (the exit shape, exh= aust augmenter and cowl flap appear to be producing some negative pressure = in the cowl)
>>     I=E2=80= =99ve currently stuffed the gear opening full of pillows and rags to emulat= e the gear being up and door closed.
>>
>> So here is the detail:
>> The 193 inch^3 oil cooler is fed by a 7.4 inch^2 inlet we= ll below the spinner and into a trumpet diffuser.
>> The 540 inch^3 water cooler is fed by the 16.5 inch^2 right chee= k inlet very close to the spinner and into a trumpet and then wedge diffuse= r. (Tried to copy Tracy=E2=80=99s RV8 cooler design)
>> Ive put a matrix of wool tufts over the back of the water cool= er and distribution appears quite even.
>> = See photo showing oil cooler inlet below spinner vs cheeks.
>> Currently the oil temps lag the water temps by a good 3= 0F.
>>
>> = So next opportunity I=E2=80=99m thinking:
>>= ; 1. Because its a quick and easy test, I=E2=80=99m planning to close off p= art of the oil cooler inlet and see what this does to the water temps.
<= /div>
>> Will this provide a better balance between o= il and water with the water rad getting a better share of the exit air flow= ?
>>
>> 2.= Seek to plot a set of pressure measurements at various locations around th= e cowl and diffusers for various;
>> 1. RPM= =E2=80=99s
>> 2. Cowl Flap position
>> 3. Gear door open / closed (stuffed full of pil= low and rag).
>>
>> Many thanks for your ponderings and any of your thoughts.
>>
>> Cheers
<= /div>
>>
>> Steve
>> Perth Western Australia
>> Glasair Super IIRG - Renesis 4 port RD1C EC3 EM3
>>
>>
<= div dir=3D"ltr">>>
>>   &n= bsp; <VH-EXPsmall.jpeg>
>> 
=
>>> On 28 Dec 2017, at 7:37 am, Stephen Ize= tt stephen.izett@gmail.com <flyrotary@= lancaironline.net> wrote:
>>>
>>> Hi Steve
>= ;>>
>>> Aeroplane has not flown. = We are still testing on the ground in OAT=E2=80=99s of 80-100F
>>> At idle (1900rpm) Delta T=E2=80=99s across Oil c= oiler - 18F, Water coiler - 8F
>>>
<= /div>
>>> We are seeking to do two things:
>>> 1. Review our design - have we made a clear= mistake somewhere -
>>> a. We managed t= o not have an air bleed at the engine coolant in/out which is the highest p= oint!
>>> We only have returns to the pr= essurised expansion tank/cap from rear iron and one from the top of the rad= iator in tank (returning to pump in).
>>>= ; b. We do not have a small hole in the Renesis bypass which we plugged.
>>> c. Lynn uses a restrictor in the outle= t to make sure the pump isn=E2=80=99t cavitating. Our coolant out plumbing = has far less restriction than the stock setup (All be it the radiator is a = dual pass so presents  significantly more resistance)
>>> d. We have just finished building a cowl flap in an = attempt to control cowl pressure.
>>>
>>> 2. Do the science and seek to measure= what the air and water are doing.
>>> a= . Not sure how to measure the water flow easily.
>>> b. We are testing today to see what air pressures exist aroun= d the diffusers and cowl.
>>>
=
>>> Cheers
>>>=
>>> Steve
&g= t;>>
>>>> On 28 Dec 2017, at 3= :00 am, Steven W. Boese SBoese@uwyo.edu <flyrotary@lan= caironline.net> wrote:
>>>>
>>>> Simply determining radiator coola= nt delta T may be useful in troubleshooting the cooling system.  The w= ater cooling system is a closed system with two heat exchangers: one is the= engine putting heat into the coolant and the other is the radiator removin= g heat from the coolant.  When all of the coolant flows through the en= gine and radiator (coolant bypass passage blocked by either a plug or a ful= ly open thermostat) the engine and radiator must have the same coolant delt= a T.  At a given power level and coolant flow rate we all should see s= imilar delta T's since we are using very similar engines.  At sea leve= l full throttle, that coolant delta T should be close to 15 degrees F. = ; Since the heat exchanger characteristics of a clean engine are essentiall= y fixed, a coolant delta T of much more than15 degrees F at full throttle w= ould most likely be a result of insufficient coolant flow rate through the = system.  This could result from a defective water pump or too much coo= lant bypassing the radiator such as due to an incompletely closed thermosta= t bypass passage, too large air bleeds from engine coolant high points, or = an open cabin heater coolant loop.  An EWP would introduce an addition= al variable. 
>>>>
>>>> With proper coolant flow rate, when the rad= iator cannot remove enough heat from the system, the overall coolant temper= ature will rise until one of two conditions are achieved.  First, the = radiator may be capable of removing enough heat with a greater delta T betw= een the coolant and the air.  The system will stabilize, but the delt= a T's of the coolant across the engine and across the radiator will remain = essentially equal and unchanged.  This type of behavior is demonstrate= d in the attached data plot for a full throttle climb from 7,000 to 14,0000= ft msl with a typical OAT decrease.
>>>= >
>>>> The second condition would= be to boil the coolant and remove heat due to the phase change.  This= may not maintain a closed system and the stable condition would then, of c= ourse, be temporary.
>>>>
<= div dir=3D"ltr">>>>> The goal of designing the radiator side of= the cooling system is to size the radiator and air flow through its core t= o achieve the desired overall coolant temperature.  Trying to change t= he coolant delta T at a given RPM and power level will prove frustrating.
>>>>
>&g= t;>> The same would be true of the oil cooling system if the oil flow= rate was consistent between our systems.  However, if part of the oil= flow is returned to the sump at the front cover relief valve, comparisons = between different setups will be of limited value unless the actual oil flo= w rates through the oil coolers are known. 
>>>>
>>>> Steve Boese
>>>> RV6A, 1986 13B NA, RD1A, EC2
<= /div>
>>>>
>>&= gt;>
>>>> <coolant delta T.jpg= >--
>>>
>>&= gt;
>>> --
&g= t;>> Homepage:  http://www.flyrotary.com/
>>
=


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