Thank you. What about the effect of the altitude on the parasite drag? How does it decrease? Why does (Thrust-Drag) increase with altitude up to the tropopause (at least for turbojet)?
It will increase because the engine needs more and more power as you go up, so the you will need more airspeed to compensate. Therefore, more parasite drag in the same airspeed from 5000 feet than 50000 feet
As you increase your altitude,you would need fly at a higher airspeed to compensate for decreasing in density or you could say the air is starting to be incompressible
Thanks for the video which is very informative. However, I do feel that you are explaining profile drag and not parasite drag- maybe this is the pilots take on it and not the engineers/aerodynamicists take. I understand parasite drag as that drag occurring from non lifting parts of the aircraft,nacelles,nose cones,aerials etc and profile drag or zero lift drag should be used to explain form drag ,skin friction drag and interference drag. To make total drag one would then need to add induced or lift dependent drag. Just an observation/idea not meant as a criticism.
