Mailing List flyrotary@lancaironline.net Message #28650
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Re: Tracy, Ed, delta T
Date: Wed, 21 Dec 2005 12:34:33 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Tracy, to compare apples and apples, I would recommend the same IAS, that way the dynamic pressure on the cores should be about the same at both altitudes.
 
Ed A
 
----- Original Message -----
Sent: Wednesday, December 21, 2005 10:33 AM
Subject: [FlyRotary] Re: Tracy, Ed, delta T

Good question Monty but I don't know.  Only looked at it down low on hot days.  I'l try the following experiment next time I fly:
 
Set fuel burn at a constant value (for roughly the same BTU rejection in both cases).  Measure delta T at 1000 ft then at 8000 ft.  Airspeed should also be similar.  Do you think IAS or TAS should be the target?
 
Tracy
----- Original Message -----
Sent: Tuesday, December 20, 2005 8:36 PM
Subject: [FlyRotary] Tracy, Ed, delta T

Tracy and Ed,
 
I was looking at an earlier post where Tracy listed air delta T across his evap cores in cruise as 70-80F. How much increase in DeltaT do you see with altitude? I would assume it would increase since the air is both colder, and thinner. A 10 deg deltaT change makes a substantial difference when sizing an intake.
 
Monty
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster