Received-SPF: pass
 receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com
Message-ID: <000f01c6275e$a44fcc60$2402a8c0@edward2>
From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-963624@logan.com>
Subject: Re: [FlyRotary] Re: Suitability of NPG for Rotary Engine use
Date: Wed, 1 Feb 2006 13:38:05 -0500
MIME-Version: 1.0
Content-Type: text/plain;
	format=flowed;
	charset="iso-8859-1";
	reply-type=response
Content-Transfer-Encoding: 7bit


----- Original Message ----- 
From: "Ernest Christley" <echristley@nc.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Wednesday, February 01, 2006 12:11 PM
Subject: [FlyRotary] Re: Suitability of NPG for Rotary Engine use


> Ed Anderson wrote:
>
>> Ernest, my admittedly limited understanding of thermo properties leaves 
>> me to believe that specific heat already takes into consideration the 
>> different in density.  In otherwords, the specific heat factor specifies 
>> how much heat it takes to raise a fixed amount of a material (cubic CC?) 
>> 1 degree. Therefore, the role density plays is already taken into account 
>> by determining the specific heat of the material.  At least that is my 
>> understanding.
>
> The units in the chart are given as Btu/lb/*F, so that is the amount of 
> heat necessary to raise the temperature of certain mass.  A higher density 
> will allow more mass to pass by at the same flow rate.  I don't think the 
> 10% difference in density would change your conclusions (which I think are 
> valid), but it would help explain the discrepancy in their performance 
> numbers.
>
> -- 
Ok, I see what you mean. I'm not certain to be honest.  But your are right 
in that  Q = cp*Mass*DeltaT, so if Mass goes up so does heat transfer.  So 
that certainly helps in that direction.

Ed