Major A writes: > > This is probably obvious, but according to my study materials for the > > instrument rating, the efficiency of a jet engine depends on the > > temperature differential between its combustion and the outside air > > temperature -- that's why jets are very efficient flying near the > > tropopause at around -60 degC, but burn more fuel for less power in > > warmer temperatures (i.e. lower). Is YASim taking that into account? > > Just out of interest, what material is this (who wrote/published it)? > Does it give a formula, or at least a reason for this? (I'm asking > because I suspect that the author got something very wrong here.)
It's from the Canadian Forces Air Command Weather Manual (which is quite good, at least for weather). Here's the relevant passage: The performance of an aircraft depends on several factors, among which temperature is important. The efficiency of a jet engine depends in part on the difference between the outside air temperature and the maximum temperature attainable in the combustion chamber. When the air temperature increases above a certain value, depending on the altitude, the true airspeed and the aircraft efficiency both fall off, the aircraft's operating height is reduced and there is an increase in fuel consumption per mile. All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
