Jet efficiency at high altitudes
Doing some reading here and trying to define why a jet is more efficient than a TP at high altitudes...?
In conclusion, I found that:
A turbo prop is only efficient up to a certain altitude, beyond which you will get no increase in specific fuel consumption and SAR. This is due to thrust decreasing with increasing TAS at a lower altitude than a jet.
Jet engine is more efficient at altitude due to better thermal efficiency and air being less dense. Better SFC and SAR higher up you go, unlike a TP where it starts to flatten off?
Can we also assume that increasing TAS is also limited by propellor tip speed on a TP?