Timeline for Why does this formula say rocket efficiency depends on velocity?
Current License: CC BY-SA 4.0
5 events
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| Aug 1, 2023 at 3:20 | comment | added | Infinite_Maelstrom | Why would adding a lot of inert propellant worsen the mass fraction? Since it's still propellant, it doesn't get counted when determining m_final. | |
| Apr 29, 2020 at 23:28 | comment | added | Christopher James Huff | An odd fact that follows from this: a rocket that varied its exhaust velocity to precisely match its instantaneous velocity would be 100% energy efficient...it would leave a trail of stationary exhaust and it and its payload would end up with all the kinetic energy. Or it would if it could start moving with an exhaust velocity of 0. Energy efficiency isn't a very useful figure with rockets, but it's noteworthy that staged launch vehicles often do approximate this in the end, with high-specific impulse upper stages on top of high-thrust lower stages. | |
| Apr 29, 2020 at 20:30 | comment | added | Mark | In short, rockets usually operate in situations where there's an abundance of energy, and the concern is about the efficiency of turning mass into rocket movement. Jet engines operate in situations where mass is abundant, so the concern is about efficiently turning energy into movement. | |
| Apr 29, 2020 at 13:06 | history | edited | user20636 | CC BY-SA 4.0 |
added 319 characters in body
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| Apr 29, 2020 at 12:58 | history | answered | user20636 | CC BY-SA 4.0 |