Subject: [FlyRotary] Re: Cooling oil

 

 

----- Original Message -----

From: "Joseph Berki" <joseph.berki@grc.nasa.gov>

To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>

Sent: Thursday, June 10, 2004 12:39 PM

Subject: [FlyRotary] Re: Cooling oil

 

 

> It would be interesting to measure flow in both engines.  I thought that

> both Lycoming and Mazda engines rejected 2/3 heat load through the

> oil  that is why I started going down this road.  If the engines generated

> the same Hp than the heat load should be similar.

>

> Joe Berki

 

Joe, both engines may generate the same heat load, but the proportion

rejected through the coolant in case of the Mazda is 2/3 of its waste heat

while the oil rejects another 1/3 of the waste heat.  Neither engine rejects

anywhere near 2/3 of its waste heat through the oil.

 

Most aircraft engines reject on the order of 300-600 BTU/Min through the

oil, the Mazda at 160HP rejects approx 2446 BTU/Min through the oil.

 

Ed Anderson

 

Ed;

 

That number looked a bit high to me, so I went in to my file to check.  My data shows 28% of the fuel burn energy in the rotary gets converted to HP, 18% goes to the coolant, and about 7% to the oil. Most of the rest goes out the exhaust pipe. For 160 HP output, I think that should be 1725 BTU/Min going to the oil cooler.  So about 3 times the comparable powered Lyc.

 

Double check me on this.

 

Al