User:Milton Beychok/Sandbox: Difference between revisions
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Thrust is the [[force]] ('''''F''''') which moves a rocket through the air. Thrust is generated by the rocket engine through the reaction of [[acceleration|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:<ref>[http://exploration.grc.nasa.gov/education/rocket/rktthsum.html Rocket Thrust Summary] from a website page of the [[National Aeronautics and Space Administration]] (NASA)</ref><ref>[http://exploration.grc.nasa.gov/education/rocket/specimp.html Specific Impulse] from a website page of the National Aeronautics and Space Administration (NASA)</ref> | Thrust is the [[force]] ('''''F''''') which moves a rocket through the air. Thrust is generated by the rocket engine through the reaction of [[acceleration|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:<ref>[http://exploration.grc.nasa.gov/education/rocket/rktthsum.html Rocket Thrust Summary] from a website page of the [[National Aeronautics and Space Administration]] (NASA)</ref><ref>[http://exploration.grc.nasa.gov/education/rocket/specimp.html Specific Impulse] from a website page of the National Aeronautics and Space Administration (NASA)</ref> | ||
:<math>F = \dot {m} V_e + (p_e - | :<math>F = \dot {m} V_e + (p_e - P_o)A_c</math> | ||
and also this form, by defining a new term '''''v<sub>eq</sub>''''' : | and also this form, by defining a new term '''''v<sub>eq</sub>''''' : | ||
:<math>F = \dot {m} V_{eq} = \dot {m} \left [V_e + \frac {(p_e - | :<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 of propellant burning: | The total impulse of a rocket is defined as the average thrust multiplied by the total time ( '''''t''''' ) of propellant burning: | ||
:<math>I = F \Delta | :<math>I = F \Delta t = \int {F dt} = \int {\dot {m} V_{eq}\, dt} = \dot {m} V_{eq}</math> | ||
The specific impulse ( '''''I<sub>sp</sub>''''' ) is the total impulse divided by the [[weight]] of the exhaust gas: | The specific impulse ( '''''I<sub>sp</sub>''''' ) is the total impulse divided by the [[weight]] of the exhaust gas: | ||
Revision as of 16:49, 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 :
![{\displaystyle F={\dot {m}}V_{eq}={\dot {m}}\left[V_{e}+{\frac {(p_{e}-P_{o})A_{c}}{\dot {m}}}\right]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3b089a2f1190670a291d1d87de354f028ceb06f6)
The total impulse of a rocket 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)