Mailing List flyrotary@lancaironline.net Message #29946
From: Chad Robinson <crj@lucubration.com>
Subject: Re: [FlyRotary] NPG Coolant Temperature vs 50/50
Date: Sat, 04 Feb 2006 21:05:11 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Ed Anderson wrote:
Delta T = Q/cM, now if the combined effects of c and m  provide 13% less heat transfer capability than the 50/50 mixture that would indicated that to carry away the same Q at the same flow rate, the delta T of NPG+ would need to increase by 13%.  So if I were getting 180F with the 50/50 for the same Q load (and flow rate) then with NPG+,  I would expect 180 *1.13 = 203F.  Yet, if I understood correct we have reports  that lesser temperatures results noted by users of NPG - this leaves me a bit puzzled.

I don't have the answer, but how about a hypothesis? Suppose they have a cavitation problem. A more viscous fluid tends to reduce the onset of cavitation, no? And is there any data on what pressure their system is being run at?

Regards,
Chad
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