What is total impulse? - Space Exploration Stack Exchange
2017年3月26日 · If you use twice as much fuel, the total impulse might be roughly double, but that doesn't mean the engine is better. So you can divide total impulse by the mass of the fuel used in the particular test. The result is called specific impulse or impulse per unit mass. It turns out the specific impulse is the average effective velocity of the ...
rockets - Calculating propellant mass from total impulse - Space ...
2022年11月16日 · Honestly, I'd ignore the total impulse and start with the thrust instead. Take the rocket thrust equation. Thrust $=\dot{m}V_e + (p_e-p_0)A_e$ Solve for $\dot{m}$, the mass flow rate through the nozzle, then integrate THAT in time for your total mass used in the burn.
rockets - What is the story behind specific impulse being …
2020年1月28日 · Total impulse is just force times the duration of the force (time), which is equal to the momentum imparted to the object the force is applied to. But in the early days in the US, propellant quantities were measured on scales calibrated in pounds , or more accurately, pounds-force : the force resulting from one Earth g acting on one pound-mass .
Rocket Propulsion Elements: Total Impulse Problem
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Why is specific impulse equivalent to effective exhaust velocity?
2020年12月5日 · So if we had a rocket of 1000 kg, that had a fuel tank of 1000 kg, where mass would magically reappear so that its total mass remained 1000 kg even when expelling fuel, and this rocket had engines with a specific impulse of 4 km/s, we can now conclude that this rocket could reach a maximum speed of 4 km/s. Now such a rocket is impossible.
How do I get Specific impulse in (s) from (N * s/kg)?
2018年2月15日 · Specific impulse 2314 N·s/kg A Newton has units of kg m / s^2, so that is kg m s / s^2 kg which is m/s, and 2314 m/s is a reasonable value for an effective exhaust velocity. According to the Wikipedia subsection Specific impulse as …
propulsion - Thrust in Newtons to specific impulse - Space …
2019年12月30日 · Thrust in newtons is equal to the propellant mass exhaust flow rate in kg/s times the specific impulse in N·s/kg (which is dimensionally equivalent to m/s), however. You more often see specific impulse given in seconds; multiply seconds by 9.81 to get N·s/kg. Note that the use of standard gravity as a conversion factor does not mean that ...
physics - How should mass specific impulse calculated for …
2020年10月27日 · From Wikipedia's Specific impulse: By definition, it is the total impulse (or change in momentum) delivered per unit of propellant consumed and is dimensionally equivalent to the generated thrust divided by the propellant mass flow rate or weight flow rate.
engine design - In the context of calculating mass flow rate from ...
Specific impulse (usually abbreviated Isp) is a measure of how effectively a rocket uses propellant or jet engine uses fuel. By definition, it is the total impulse (or change in momentum) delivered per unit of propellant consumed [1] and is dimensionally equivalent to the generated thrust divided by the propellant mass flow rate or weight flow ...
What is the "specific impulse"? - Space Exploration Stack Exchange
This way you can get the specific impulse. 3) $\Delta v = I_\text{sp} g_0 \ln \frac {m_0} {m_f}$ This is what this whole game is all about - where you make practical use of that painstakingly determined specific impulse. Delta-v is the actual milleage of a …