Recent content by LT72884

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    B Which equation should be used to calculate impulse: I=F(t) or I=m1v1-m0v0?

    correct, there is no controversy :) i thank you for your help aand guidance. it is much appreciated.
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    B Which equation should be used to calculate impulse: I=F(t) or I=m1v1-m0v0?

    correct, i understand what you are saying :) but rocket motors are so small that 3.5g of changing mass is almost negligible. yes, this is for zero drag modeling only. I was just mentioning i can find Cd various ways etc. ill have to look at your reply again. I did find a book online last...
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    B Which equation should be used to calculate impulse: I=F(t) or I=m1v1-m0v0?

    this is just for simple estimates. I do know i would have to integrate etc, but for simplicity, you can use the big 3 to solve for velocity. Vf = Vi = at Vi = 0 so Vf is acceleration * time i know the acceleration of the rocket motor i9n basic simple terms a= (Thrust - weight)/mass according...
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    B Which equation should be used to calculate impulse: I=F(t) or I=m1v1-m0v0?

    good point. I do agree with that. I need to take account of the net force everywhere, not just acceleration. This works if i know the impulse, and force, which i do, but if i am only given impulse and time, then i have to find the thrust. EDIT: for the first equation, i can not use 5.95N like...
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    B Which equation should be used to calculate impulse: I=F(t) or I=m1v1-m0v0?

    without getting into ODEs and numerical methods, the 5.95 newtons is the amount of thrust the small rocket motor produces. Most likely constant for rough estimates of zero drag flight i found this article which uses the smae method...
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    B Which equation should be used to calculate impulse: I=F(t) or I=m1v1-m0v0?

    for second equation it would be v = (2.5*9.81)/(0.0357*9.81) = 70.02m/s = 229 fps, not 206. good catch. however, if i do it in freedom units, i do get 206 v= (0.5056*32.2)/0.0787Lbs = 206.86 f/s for eq 1 its a =(thrust-rocket weight)/mass then v = u +at u =0 a= 156.86m/s^2 t= 0.42 seconds v...
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    B Which equation should be used to calculate impulse: I=F(t) or I=m1v1-m0v0?

    Just going over some basic equations to help someone out and i have noticed that i get 2 different answers when using 2 different but very similar equations for impulse. first eq. I=F*t lets say that i have a small rocket motor that has a force of 5.95 newtons and a impulse of 2.5 n-s...
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    I Finding the equation of a curved line

    i have been messing around with desmos and started to add functions together. y=sqrt(x) -x -x^2 and things like this. but y=sqrt(x)-x produces a nice curve, then i went all fancy from an equation found in my airfoil design book. How the heck did they discover this equation back in the 50's...
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    I Finding the equation of a curved line

    yes, how is this done manually with no computer help. also what is this least squares method? thanks
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    I Finding the equation of a curved line

    yeah, its coming up with the functional shape thats tough to do haha. i mean, how did engineers do this in the past before computers did curve fitting? thanks
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    I Finding the equation of a curved line

    Ok, so i have done many math classes, as i am an engineer, however, a theory class and proof class i h ave not done, except maybe one haha. here is my question, if i draw some sort of curved line by hand, how do i find an equation for that? for example, i draw half of a tear drop but along...
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    Understanding fatigue and ultimate loading

    im going to try and submit a bug report. Reason being, after reading multiple studies and research papers over the course of the last 8 or 9 days, my results for the first simulation fall within the same range as the papers. However, at the slower wind speeds, the papers ultimate load didnt...
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    Understanding fatigue and ultimate loading

    i have about 60 hours into it so far. Since i cant see the coding, i cant see what happens when i change one single variable like the wind speed. I guess i can ask the developer and see what he says. I have read a lot of the user documentation that NREL wrote, but it doesnt always explain...
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    Understanding fatigue and ultimate loading

    Yes I am a student haha. The user manual for openfast and mlife say "ultimate load" The dev of OPENFAST told me via the GitHub forums that ultimate load can be found 2 ways. First is FEA And second is by taking the max load of the time series data, and scaling it by a factor, until your...
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    Understanding fatigue and ultimate loading

    I highly appreciate the help and willingness to find a better solution. I agree that its been a pain the last few weeks.
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