|
I promised to report my indicated water temps next chance I got.
Here are some samples:
OAT(F) Delta T (F)
69
23
66
19
68
10
75
14
65
15
75
7
77
12
All figures are in cruise at 8,000 to 10,000 MSL. Last
reading was in climbout, but not much difference. I really can't
explain the range of readings, but that is what it read!
Thanks for the data, Bill
I ran it through my model, but did
not have your power or fuel burn or airspeed. But assuming
you were doing approx 140 Indictated air speed at altitude and modest
power (5200 rpm) my figures shows a delta T of 12.27F. If you were
running a bit harder the delta T would go up a bit. If you were
moving faster than 140 indicated at 5200 rpm then it would go down a
bit.
For climb I assumed 120 Indicated and a minimum of
130HP this gave me a delta T of 24F for the radiators. Both
figures not too far off from what you are reporting.
So the delta T would seem to be dependent on your
power setting and air speed most of all. The more BTUs of heat you
reject into the same amount of mass flow, the greater the delta T.
However, the faster you go the more cooling mass flow you get which
appears to help to hold down the delta T.
In any case, appreciate the data
Ed Anderson
|