KC135DELTA
Well-Known Member
- Joined
- Aug 1, 2006
- Messages
- 112
I have a question that may be utterly stupid or not, I dont know:
When say a jetliner increases in altitude, the air density decreases, which in turn decreases the drag, with the exception of wave drag. This allows high flying aircraft such as the U2 to get up into it's coffin corner where it is close to it's critical mach number and stall speed due to the slowing of the sound barrier with altitude and raising of the stall speed. But aircraft like supersonic fighters don't have a critical mach number, or it is very high. But say they were able to increase their speed proportionately with their increase in altitude so say an indicated 350knots at 100,000ft which is very very fast due to the low air density, and with this high speed flight in the low drag environment the engines should be passing through enough air to breath just as well as they would doing 350knots at say 20 or 30k right? So as long as a jet can maintain the lift needed to reach these altitudes and the power to overcome it's own wave drag it should be able to cruise at very high speeds very efficiently no?
When say a jetliner increases in altitude, the air density decreases, which in turn decreases the drag, with the exception of wave drag. This allows high flying aircraft such as the U2 to get up into it's coffin corner where it is close to it's critical mach number and stall speed due to the slowing of the sound barrier with altitude and raising of the stall speed. But aircraft like supersonic fighters don't have a critical mach number, or it is very high. But say they were able to increase their speed proportionately with their increase in altitude so say an indicated 350knots at 100,000ft which is very very fast due to the low air density, and with this high speed flight in the low drag environment the engines should be passing through enough air to breath just as well as they would doing 350knots at say 20 or 30k right? So as long as a jet can maintain the lift needed to reach these altitudes and the power to overcome it's own wave drag it should be able to cruise at very high speeds very efficiently no?
