X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost02.isp.att.net ([204.127.217.102] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2374437 for flyrotary@lancaironline.net; Sun, 07 Oct 2007 21:53:21 -0400 Received-SPF: pass receiver=logan.com; client-ip=204.127.217.102; envelope-from=bbradburry@bellsouth.net Received: from arptk8ng400 (adsl-146-123-217.mco.bellsouth.net[72.146.123.217]) by bellsouth.net (frfwmhc02) with SMTP id <20071008015244H02000k7uce>; Mon, 8 Oct 2007 01:52:44 +0000 X-Originating-IP: [72.146.123.217] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" In-Reply-To: Subject: RE: [FlyRotary] Re: New Spreadsheet Details Date: Sun, 7 Oct 2007 21:52:48 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000A_01C8092C.672491C0" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 Thread-Index: AcgJOVq6crHzra59T+uRHXGFXWpbNgAFFjiQ X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16480 Message-ID: This is a multi-part message in MIME format. ------=_NextPart_000_000A_01C8092C.672491C0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Personally, I think he is just your common ordinary damn genius! Bill B _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich Sent: Sunday, October 07, 2007 7:25 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: New Spreadsheet Details Ed, How can I say no! with my single rotor development I was hoping you might help me with radiator size, perhaps with a bit of guidance I will be able to use your spread sheet. Please pass to lendich@optusnet.com.au BTW Ed are you and engineer, an ex-maths teacher, or someone who just loves working on problems? George (down under) I attempted 3 times to post the new spreadsheet to the list, but it is a few KB too large. So those of you who may want it, send me an e mail to eanderson@carolina.rr.com with the subject : Spreadsheet . I will send you a copy. Details of latest revisions. In the past, I have provided a spreadsheet to aid in determining power, fuel flow, heat produced, etc, and have also attempt to provide some rudimentary cooling calculations. You can entertain yourself with it as well with your dream engine {:>) Since there was no engine load component in earlier spreadsheets, I had provided % throttle opening factor as a substitute. However, that was never satisfactory because who of us know exactly what % throttle opening we have at any point and besides that throttle opening does not necessarily correspond to load. In any case, I recent revised the spreadsheet, so that a user may now put in his manifold pressure. That is generally a parameter available to most folks. It also eliminates potential errors from altitude, air density, temperature etc. It and rpm also provide a better indicator of LOAD than does throttle position. It will also works for N/A and turbo engines. All you do is enter your manifold pressure (and the other engine operating parameters) and the calculations will use that to calculate the air density in the intake and from that the power, flow rates,BTU, etc. So now the manifold air density is separate from the cooling air density which is dependent on altitude. So manifold pressure and altitude (ambient pressure) are now separate for engine operation and cooling operations. So in the cooling section you must now enter your altitude for cooling calculations. Also, I have now provided for the user to enter the dimensions of his cooling cores and the number rather than the default Gm cores and RX-7 oil cooler I had been using. You can change these parameters on the second sheet titled "Cooling Calculations", it shows recommended default values (the GM cores and Stock Rx-7 cooler) just to get you started or if your project is still in the dream stage. Also there is provision on the cooling calculations sheet to have your coolant flow rate proportional to engine rpm (more realistic). The flow rate is based on Racing Beat information for 1974 and later coolant pump flow rate. If you have changed the pulley ratio to non-stock then these flow rates may be off a bit - but still more realistic than assuming a 40 gpm flow rate at idle and at 6000 rpm {:>). So these changes mean you can now simulate a partial throttle operation say at 19" Hg and a cooling altitude at 7500 MS. You can now see if your system should be cooling at that power setting and then you could change the power setting to 22" Hg and see if you installation should still cool at that selected air speed and altitude and power setting. Manifold pressure and Air Fuel Ratio can make a considerable difference in the amount of heat produced. So pay attention to the values you are using. Now here is the potential problem I can see. If you tell the spreadsheet you are flying at 7500 MSL in the cooling data input, but you decide to use WOT for your engine, you must realize that the ambient pressure (and therefore your manifold pressure) at that altitude will not be 29.92 " HG. Your manifold pressure (for N/A engine) would never be that high for an N/A engine at that altitude - but, it could be for a turbo engine. So unless you selected YES for turbocharged in the data entry area, an error message will be displayed "Manifold Pressure exceeds ambient". It can also happen if you have already selected a manifold pressure say 29" while at sea level, but then you enter 2000 MSL for altitude in the cooling section. The warming message will inform you that your manifold pressure now exceeds the ambient pressure at 2000 MSL ( unless you enter turbo charged = "yes"). If you select an RPM value for the cooling section and it is outside the limits of the rpm values in your calculated data table, then an error message "Invalid RPM" will be shown in the cooling data entry area. So that would mean either change the rpm OR change the range of rpm in the table by adjusting the rpm start value or the rpm step value. As always, if anyone finds an error or problem please let me know. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html _____ No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.14.2/1052 - Release Date: 5/10/2007 6:53 PM ------=_NextPart_000_000A_01C8092C.672491C0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Personally, I think he is just your = common ordinary damn genius!

 

Bill B

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich
Sent: Sunday, October 07, = 2007 7:25 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: = New Spreadsheet Details

 

 Ed,

How can I say no! with my single rotor development I = was hoping you might help me with radiator size, perhaps with a bit of = guidance I will be able to use your spread sheet.

Please pass to lendich@optusnet.com.au

BTW Ed are you and engineer, an ex-maths teacher, or = someone who just loves working on problems?

George (down under)

I attempted 3 times to post the new spreadsheet to = the list, but it is a few KB too large.  So those of you who may want it, = send me an e mail to eanderson@carolina.rr.com with the subject :  Spreadsheet .  I will send you a = copy.

 

Details of latest = revisions.

 

In the past, I have provided a spreadsheet to aid in = determining power, fuel flow, heat produced, etc, and have also attempt to provide = some rudimentary cooling calculations.  You can entertain yourself with = it as well with your dream engine {:>)

 

Since there was no engine load component in earlier spreadsheets, I had provided % throttle opening factor as a substitute.  However, that was never  satisfactory because who = of us know exactly what % throttle opening we have at any point and = besides that throttle opening does not necessarily correspond to = load.

 

In any case, I recent revised the spreadsheet, so = that a user may now put in his manifold pressure.  That is generally a = parameter available to most folks.  It also eliminates  potential errors = from altitude, air density, temperature etc. It and rpm also = provide a better indicator of LOAD than does throttle position.   It = will also works for  N/A and turbo engines.  =

 

 

All you do is enter your  manifold pressure = (and the other engine operating parameters)  and the calculations = will use that to calculate the air density in the intake and from that the power, = flow rates,BTU, etc.  So now the manifold air density is separate from = the cooling air density which is dependent on altitude.  So manifold = pressure and altitude (ambient pressure) are now separate for engine operation = and cooling operations.

 

So in the cooling section you must now enter your = altitude for cooling calculations.  Also, I have now provided for the user = to enter the dimensions of his cooling cores and the number rather than the = default Gm cores and RX-7 oil cooler I had been using.  You can change these parameters on the second sheet titled "Cooling Calculations", it  shows recommended default values (the GM cores and Stock Rx-7 = cooler) just to get you started or if your project is still in the dream = stage.

 

Also there is provision on the cooling calculations = sheet to have your coolant flow rate proportional to engine rpm (more = realistic).  The flow rate is based on Racing Beat information for 1974 and later = coolant pump  flow rate.  If you have changed the pulley ratio to = non-stock then these flow rates may be off a bit - but still more realistic than = assuming a 40 gpm flow rate at idle and at 6000 rpm {:>).  =

 

So these changes mean you can now simulate a partial throttle operation say at 19" Hg and a cooling altitude at 7500 = MS.  You can now see if your system should be cooling at that power setting = and then you could change the power setting to 22" Hg and see if you installation should still cool at that selected air speed and = altitude and power setting.  Manifold pressure and Air Fuel Ratio can make a considerable difference in the amount of heat produced.  So pay = attention to the values you are using.

 

Now here is the potential problem I can see.  If = you tell the spreadsheet you are flying at 7500 MSL in the cooling data = input, but you decide to use WOT for your engine, you must realize that the ambient pressure (and therefore your manifold pressure) at that altitude =  will not be 29.92 " HG.  Your  manifold pressure (for N/A = engine) would never be that high for an N/A engine at that = altitude  - but, it could be for a turbo engine.  So unless you selected = YES for turbocharged in the data entry area, an error message will be = displayed "Manifold Pressure exceeds = ambient".  It can also happen if you have already selected a manifold pressure say 29" while at sea level, but then you enter 2000 MSL for = altitude in the cooling section.  The warming message will inform you that your manifold pressure now exceeds the ambient pressure at 2000 MSL ( = unless you enter

turbo charged =3D = "yes").

 

If you select an RPM value for the cooling section = and it is outside the limits of the rpm values in  your calculated data  table, then an error message "Invalid = RPM" will be shown in the cooling data entry area.  So that would mean = either change the rpm OR change the range of rpm in the table by adjusting the = rpm start value or the rpm step value.

 

As always, if anyone finds an error or problem please = let me know.

 

Ed

 

Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda/index.html=

No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.488 / Virus Database: 269.14.2/1052 - Release Date: = 5/10/2007 6:53 PM

------=_NextPart_000_000A_01C8092C.672491C0--