User:Milton Beychok/Sandbox: Difference between revisions
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:<math>F = \dot {m} V_{eq} = \dot {m} \left [V_e + \frac {(p_e - P_o)A_c}{\dot {m}} \right ]</math> | :<math>F = \dot {m} V_{eq} = \dot {m} \left [V_e + \frac {(p_e - P_o)A_c}{\dot {m}} \right ]</math> | ||
The total impulse of a rocket is defined as the average thrust multiplied by the total time ( '''''t''''' ) of propellant burning: | The total impulse of a rocket ( '''''I''''' ) is defined as the average thrust multiplied by the total time ( '''''t''''' ) of propellant burning: | ||
:<math>I = F \Delta t = \int {F dt} = \int {\dot {m} V_{eq}\, dt} = \dot {m} V_{eq}</math> | :<math>I = F \Delta t = \int {F dt} = \int {\dot {m} V_{eq}\, dt} = \dot {m} V_{eq}</math> |
Revision as of 18:50, 24 March 2010
Rocket thrust and specific impulse
Thrust is the force (F) which moves a rocket through the air. Thrust is generated by the rocket engine through the reaction of accelerating a mass of gas. The gas is accelerated to the the rear and the rocket is accelerated in the opposite direction. Force may be mathematically expressed as:[1][2]
and also this form, by defining a new term veq :
The total impulse of a rocket ( I ) is defined as the average thrust multiplied by the total time ( t ) of propellant burning:
The specific impulse ( Isp ) is the total impulse divided by the weight of the exhaust gas:
- ↑ Rocket Thrust Summary from a website page of the National Aeronautics and Space Administration (NASA)
- ↑ Specific Impulse from a website page of the National Aeronautics and Space Administration (NASA)