Questions in relation to the design of Rockets


by trfinck
Tags: fuel, propellant, rocket, space, weight
trfinck
trfinck is offline
#1
Feb16-12, 04:49 PM
P: 3
Hey everyone, I'm in the process of designing a rocket that could achieve high(er) altitudes. Of course, I want to make the rocket as small as possible, but maximize the height. I understand that the Mass fraction of the craft should be 0.91, where 91%~ is fuel/propellant, 6%~ is payload, and 3% is structural.

My basic question is, assuming my initial weight(total) was around 500kg, what would be the best propellant/fuel to get the most distance? (cutting out factors such as air resistance and so forth)

Thanks in advanced!
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enigma
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#2
Feb17-12, 10:08 PM
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Your mass fraction should be as high as you can make it. It just works out that 9:1 fuel to everything else is a typical value. The final velocity (and as a result the high/distance it can travel) is entirely dependant on the specific impulse of the fuel and the mass fraction.

That said - you need to define a little bit more. Are you talking solid rocket, hybrid rocket, liquid rocket? Are you really building something, or is this a thought experiment? Does it need to be practical, or would killing a bunch of people in range of the exhaust plume be ok?


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