this data from lyc 10360 A1B  turbo (normalized) charged,  ~ 200 hp
engine...)
 

Induction Air Temperature?

 

Gents:

 

What temperature rise do you typically see across your turbo?

 

[At my typical cruise of 16,500 or 17,500 I typically see IAT of about

177 F at 28.5" and 2550 RPM, flowing about 10 GPH.]

 

After putting the IAT probe in, I've observed the temperature on four

flights.  Running at 25/25, the IAT is 160F to 170F, ~110F above ambient

(50F to 60F), at 10,500 and 11,500.  Temperature drops at lower power

settings, same altitude and external temperature.  I think I saw about

140F when I pulled the power back to21" in some turbulence.  That

doesn't seem right - if the turbo is matched to the airflow, I think

delta T should be mostly a function of the pressure rise and less so the

work input (exhaust volume through turbo, which I assume would scale

roughly 1:3 with intake flow), so I would not expect a significant

temperature change with throttle position, only with altitude.

Obviously I'm wrong.   An adiabatic rise would be ~65F to 95F depending

on the controller setpoint. (That's 13" to 19" rise, for a setpoint of

32" to 38" Hg.)

 

[It's going to be more than adiabatic, 'cause the compressor is far from

an ideally efficient machine. There have been two iterations now toward

higher efficiency... first, TurboFlite started using a different

compressor unit that was a bit more efficient at our operating point.

And now TATI is considering using the same turbo that's used in the

Cirrus install... an even more efficient unit.  As far as the throttle

change correlation, remember that your increasing mass flow through the

machine, and hence moving the turbine and compressors along their curves...]


 

Marc Wiese, 20B and 94 13B t engines