So long time ago I found myself in rocketry and now I think about Launch vehicle project for little satellite (about 2-10 lbs). Just in theory for a while.
And I've read a lot of books and projects descriptions and didn't figured out one question: how i can find required propellant masses at first steps of calculations?
There is two stage vehicle.
i tried this equation:
2nd stage propellant mass:
M(f2) = (M0*k*(exp(V/Isp))/(k+1-exp(V/Isp));
2nd stage dry mass:
M(d2) = M(f2)/k;
2nd stage total mass:
M(2)=M(d2)+M(f2);
1st stage propellant mass:
M(f1) = ((M(2)+M0)*k*(exp(V/Isp))/(k+1-exp(V/Isp));
1st stage dry mass:
M(d1) = M(f1)/k;
1st stage total mass:
M(1)=M(d1)+M(f1);
(M0 - payload mass;
k - ratio of propellant mass to dry stage mass;
V - stage delta V;
Isp - Specific impules of stage engine(s) )
But in my opinion it's very very approximate calculation.
So where I can find the right way of doing that (some kind of book) or tell me how please
And I've read a lot of books and projects descriptions and didn't figured out one question: how i can find required propellant masses at first steps of calculations?
There is two stage vehicle.
i tried this equation:
2nd stage propellant mass:
M(f2) = (M0*k*(exp(V/Isp))/(k+1-exp(V/Isp));
2nd stage dry mass:
M(d2) = M(f2)/k;
2nd stage total mass:
M(2)=M(d2)+M(f2);
1st stage propellant mass:
M(f1) = ((M(2)+M0)*k*(exp(V/Isp))/(k+1-exp(V/Isp));
1st stage dry mass:
M(d1) = M(f1)/k;
1st stage total mass:
M(1)=M(d1)+M(f1);
(M0 - payload mass;
k - ratio of propellant mass to dry stage mass;
V - stage delta V;
Isp - Specific impules of stage engine(s) )
But in my opinion it's very very approximate calculation.
So where I can find the right way of doing that (some kind of book) or tell me how please
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