Mailing List flyrotary@lancaironline.net Message #51237
From: Al Gietzen <ALVentures@cox.net>
Subject: RE: [FlyRotary] Re: alternative water pump
Date: Sun, 16 May 2010 07:07:05 -0800
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

On the water. The flow is high enough that very little temperature drop through the radiators is required to remove the heat from the engine. Q = (mass flow)*(heat-capacity)*(delta-T). If you increase the mass flow, you decrease the deltaT.  I get about a 5*F delta T on the radiators, on the other hand, the air coming out of the rads is about 100F higher than the air going in.

Bill,

Further to my query yesterday; putting some numbers on the 5o DT gives me this:

With 35 gpm, engine power is 55 hp with pure water; 40 hp with 50/50 water/EG.

 

160 hp would require 103 gpm with pure water, 143 with 50/50 water/EG.

 

What am I missing?

 

Al

 

 

 

 

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