Free Flight, Free Speech

with respect to my fuel temperature issue I might finally be up to something, see my flight test to Barcelona
http://www.jafva.com/flight/1304/

Then the simulated temps of air, fuel and oil


The oil is currently not simulated, just presumed to be a heated engine stably at 80C for now

The fuel starts basically at environment. (not at 50F, but at real environment temp) since noone was kindly chilling it down for me

Then as the engine is hot, then through the FCOC my fuel got warmed up (the cooling effect of fuel temp on oil temp not yet simulated, as again, my plane does not have a valid value of oil temp).

On my climb to cruise, as air chilled, the air cooled the fuel, but simmultaneously with the heating of the oil, the fuel is protected from going toward freezing values (@-48)

Sorry but too much fathers day present been imbibed here.... but from my work doing containerized gen sets ... isn't it 1/3rd usable power, 1/3rd exhaust and 1/3rd engine heat ?

Happy father's day bomber

IAHM-COL wrote:
Then the simulated temps of air, fuel and oil

Does this use true air temperature for exterior (this accounts for effect of speed)?

Otherwise, very nice +1

123apple wrote:Does this use true air temperature for exterior (this accounts for effect of speed)?

I have no clue.
What I'm using for "weather" temp is
/environment/temperature-degc

Which I understand it is the thermoprobe of the outside of the craft.

Heat transfer speed is deltaQ/deltat in the derivatives of heat transfer function. Which is the parameters I'm trying to optimize.

Physics majors had told us it dependent of constants given the material's properties, the distance of the gradients, the Area of heat transfer, and finally the deltaT.

bomber wrote:https://forum.flightgear.org/viewtopic. ... h&start=30

That thread was funny...as this one guy was met with basic physics formulas, didn't seem to understand them, got upset and left the discussion...

mue wrote:

bomber wrote:https://forum.flightgear.org/viewtopic. ... h&start=30

That thread was funny...as this one guy was met with basic physics formulas, didn't seem to understand them, got upset and left the discussion...

9 posts and a smart arse to boot.

bomber wrote:Sorry but too much fathers day present been imbibed here.... but from my work doing containerized gen sets ... isn't it 1/3rd usable power, 1/3rd exhaust and 1/3rd engine heat ?

Well. that'll be too hot, but I can certainly understand that the power is really linked to the combustion, which is causing TIT, from there I can use it as a source of heat that warms my fuel (but cant chill it, ie as TIT comes down oil temp doesn't as frantically), instead it slowly dissipates heat. (I assume engine oil is relatively isolated from environment, and thus the advantages of the FCOC)

Now, I got to simulate oil temp with the assumptions above, and used that to set the other portion of my FCOC simulation. After a test flight to Paris, I feel I can live with the simulated values; if something, I am too shy on the oil heat dissipation, but fix that and I'm good for now on this thermic madness.

See the plot generated from my test flight data:
http://www.jafva.com/flight/1309/


click image for larger version

IAHM-COL wrote:

123apple wrote:Does this use true air temperature for exterior (this accounts for effect of speed)?

I have no clue.
What I'm using for "weather" temp is
/environment/temperature-degc

Which I understand it is the thermoprobe of the outside of the craft.

Heat transfer speed is deltaQ/deltat in the derivatives of heat transfer function. Which is the parameters I'm trying to optimize.

Physics majors had told us it dependent of constants given the material's properties, the distance of the gradients, the Area of heat transfer, and finally the deltaT.

True air temperature is the one you want because that is what a temperature sensor will measure. It accounts for heating effect of airspeed etc.

Temperature-degC is simple atmosphere temperature (SAT).

I can get the JSBSim property for TAT later if you want, its under /fdm/jsbsim somewhere!