X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 59 [XX] (100%) SPAM TRICK: contains gapped text Return-Path: Received: from ms-smtp-04.southeast.rr.com ([24.25.9.103] verified) by logan.com (CommuniGate Pro SMTP 5.1.4) with ESMTP id 1731867 for flyrotary@lancaironline.net; Tue, 02 Jan 2007 22:50:00 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-100-190.carolina.res.rr.com [24.74.100.190]) by ms-smtp-04.southeast.rr.com (8.13.6/8.13.6) with SMTP id l033nAEp006815 for ; Tue, 2 Jan 2007 22:49:10 -0500 (EST) Message-ID: <001301c72eea$276824b0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EM2 Data Logger pix Date: Tue, 2 Jan 2007 22:49:21 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C72EC0.3E3ECC90" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0010_01C72EC0.3E3ECC90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ok, somebody has to be first to take a stab at it. How about this: Assuming the temperature measurement difference between CC and Rad-In = are not an artifact of difference between the two sensors or their = installation.... Note that the temperature divergence coincides with increased fuel = flow,increased power, and increased rpm. That means the coolant pump = rpm has approx doubled following the engine rpm increase from approx = 3000 to around 6700 rpm. The Rad -n temp divergence higher than CC = might be a results of better heat transfer to that sensor as it is = further down stream than CC sensor. This better heat transfer is a = results of more even mixing of the coolant fluid stream heat load = further away from the engine (pump). We know that turbulence increases = heat transfer over laminar (or less turbulent flow). So (speculating is = so much fun!) my hypothesis is that the second sensor is getting more = heat transferred to it due to the increased time for better mixing of = the heat load of the coolant fluid. So the average heat transfer to = that sensor is higher than the upstream sensor operating in a less = well-mixed/heat distributed flow. Note as the rpm is rapidly decreased, the red and yellow line once again = approach each other. There! I'm going to bed. Great information and data to ponder on those days when it is too nasty = to fly. Ed ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Tuesday, January 02, 2007 9:43 PM Subject: [FlyRotary] Re: EM2 Data Logger pix The JPEG is about 2 minutes of engine monitor data (from a 1 hour = log). I'd post the entire Excel spreadsheet itself but 6 meg is way too = much for up/download. The X axis is in Time (seconds) and Y is the = value. Note that some of the parameters (like rpm and fuel flow) are = scaled so they fit the Y scale of the chart A few details about flight conditions so the data can be placed in = context. The chart starts with the plane at minimum power for level = flight (MPLF) at around 1500 ft with all temperatures and pressures = stabilized. The throttle is opened to max (notice that fuel flow goes = from 3 gph to ~18 gph) and the airspeed climbs to ~150 mph. The plane = was then pitched up into a climb at Vx to see worst case cooling = conditions. WOT is maintained for about 1 minute then reduced to MPLF = again. Most of the chart is self explanatory but there are a few interesting = and (to me) mystifying points. Note the L. Rad Air Out temperature (air = temp after passing through rad). According to Paul L., the optimum for = this parameter is 10 - 20 deg F. above ambient OAT. I wanted a lot more = than that to minimize the number of CFM required and as you can see, = mine is running as much as 127 deg F above OAT which is even more than I = figured on.=20 The real mystery is the comparisons between rad inlet temp, rad outlet = temp and C.C. coolant temp (coolant temp measured right after passing = both rotor combustion chambers). In a 2nd gen 13B the CC coolant temp = is the hottest coolant in the engine because it normally cools slightly = after passing through the cooler intake port side of the engine. This = is the rad inlet temperature. As you can see, the CC temp and rad inlet = temp start out the same. When the power is increased, the rad inlet = temp climbs faster and higher than CC in the Renesis. I assume this is = caused by the increased heat picked up from the longer exhaust ports. = It is the amount that surprises me. Study the temp differentials = between these three temps and see if you can see the mystery and make = sense of this. The Chart is pretty crowded even after I eliminated several parameters = for this jpeg but when viewing it in Excel, it is very easy to see and = identify all the data. Moving the mouse pointer to any point of any = parameter pops up a little tag showing what the item is and the exact = digital value at that point in time. Tracy -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ ------=_NextPart_000_0010_01C72EC0.3E3ECC90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ok, somebody has to be first to take a = stab at=20 it.  How about this:
 
 Assuming the temperature = measurement=20 difference between CC and Rad-In are not an artifact of difference = between=20  the two sensors or their installation....
 
 
Note that  the temperature = divergence=20 coincides with increased fuel flow,increased power, and increased = rpm. =20 That means the coolant pump rpm has approx doubled following the engine = rpm=20 increase from approx 3000 to around 6700 rpm. The  Rad -n temp = divergence higher than CC might be a results of better heat transfer to = that=20 sensor as it is further down stream than CC sensor.  This better = heat=20 transfer is a results of more even mixing of the coolant fluid = stream heat=20 load further away from the engine (pump).  We know that turbulence=20 increases heat transfer over laminar (or less turbulent flow).  So=20 (speculating is so much fun!) my hypothesis is that the second sensor is = getting=20 more heat transferred to it due to the increased time for better mixing = of the=20 heat load of the coolant fluid.  So the average heat transfer to = that=20 sensor is higher than the upstream sensor operating in a less = well-mixed/heat=20 distributed flow.
 
Note as the rpm is rapidly decreased, = the red and=20 yellow line once again approach each other.
 
There!  I'm going to = bed.
 
Great information and data to ponder on = those days=20 when it is too nasty to fly.
 
Ed
 
----- Original Message -----
From:=20 Tracy = Crook
Sent: Tuesday, January 02, 2007 = 9:43=20 PM
Subject: [FlyRotary] Re: EM2 = Data Logger=20 pix

 
The JPEG is about 2 minutes of engine monitor data (from a 1 = hour=20 log).  I'd post the entire Excel spreadsheet itself but 6 = meg is way=20 too much for up/download. The X axis is in Time (seconds) and Y = is the=20 value.  Note that some of the parameters (like rpm and fuel flow) = are=20 scaled so they fit the Y scale of the chart
 
 A few details about flight conditions so the data can be = placed in=20 context.   The chart starts with the plane at minimum = power for=20 level flight (MPLF) at around 1500 ft with all temperatures and = pressures=20 stabilized.   The throttle is opened to max (notice that = fuel flow=20 goes from 3 gph to ~18 gph) and the airspeed climbs to ~150 mph.  = The=20 plane was then pitched up into a climb at Vx to see worst case cooling = conditions.  WOT is maintained for about 1 minute then reduced to = MPLF=20 again.
 
Most of the chart is self explanatory but there are a few = interesting and=20 (to me) mystifying points.  Note the L. Rad Air Out temperature = (air temp=20 after passing through rad).  According to Paul L., the optimum = for this=20 parameter is 10 - 20 deg F. above ambient OAT.  I wanted a lot = more than=20 that to minimize the number of CFM required and as you can see, mine = is=20 running as much as 127 deg F above OAT which is even more than I = figured=20 on. 
 
The real mystery is the comparisons between rad inlet temp, rad = outlet=20 temp and C.C. coolant temp (coolant temp measured right after = passing=20 both rotor combustion chambers).  In a 2nd gen 13B the CC = coolant=20 temp is the hottest coolant in the engine because it normally cools = slightly=20 after passing through the cooler intake port side of the engine.  = This is=20 the rad inlet temperature.  As you can see, the CC temp and rad = inlet=20 temp start out the same.  When the power is increased, the rad = inlet temp=20 climbs faster and higher than CC in the Renesis.  I assume this = is caused=20 by the increased heat picked up from the longer exhaust ports.  = It is the=20 amount that surprises me.  Study the temp differentials between = these=20 three temps and see if you can see the mystery and make sense of = this.
 
The Chart is pretty crowded even after I eliminated several = parameters=20 for this jpeg but when viewing it in Excel, it is very easy to see and = identify all the data.  Moving the mouse pointer to any point of = any=20 parameter pops up a little tag showing what the item is and the exact = digital=20 value at that point in time.
 
Tracy

--
Homepage:  http://www.flyrotary.com/
Archive and=20 UnSub:  =20 http://mail.lancaironline.net/lists/flyrotary/
------=_NextPart_000_0010_01C72EC0.3E3ECC90--