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I`m more used to the math.stackexchange so i really don't know how much information about my problem i should provide, if it is not enough i'll add more.

So, basically i already have a 6DOF trajectory simulator, with the drag and lift forces being considered, but i wanted to add the wind forces, on the early stages and on the descend stage, but i dont know how to properly add them on my ODE system. All my forces are calculated with the referential on the rocket center of gravity, so is the velocity.

My first tought was to consider an additional drag force by decomposing wind force in axis, but i have no idea if it is correct and if i can find the drag coefficients for each plane. Is this a correct approach?

I also saw some articles using the real velocity as the sum of the rocket velocity and the wind velocity, but in my mind this is an odd approach and i can't see how is it correct.

Any toughts on how to solve this problem, with an way that a i can actually collect the data i need to simulate it properly (ex: drag coefficients)?

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  • $\begingroup$ Why do you think it is incorrect to add the wind and rocket velocity? In what reference frame are you solving for the motion? $\endgroup$
    – tpg2114
    Oct 5, 2019 at 19:48
  • $\begingroup$ @tpg2114 im solving for the center of gravity of the rocket (at the point im not considering its change due to the loss of mass), but is the rocket real velocity the sum of these two? $\endgroup$ Oct 5, 2019 at 19:50

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Correct, the force from the wind is physically indistinguishable from a drag force. But, fortunately, the wind speed is much smaller than the speed of the rocket, so it seems to me you could just add $v_w \times t$ to the x-position of the rocket and that should be enough.

This is the best approach, until the moment when you will realize that the rocket does not always fly with its nose straight ahead, meaning there can be nonzero angle between the velocity vector and the nose direction of rocket. Unfortunately, if you start digging deeper, and try to take this into account, you are going to end up with needing a full fluid-mechanics simulator.

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  • $\begingroup$ I Get that, the main point is finding the range the Rocket may fall, and with Parachutes on the speed reduces $\endgroup$ Oct 6, 2019 at 14:25
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    $\begingroup$ On second thought, unfortunately, if this is an amateur rocket which returns back to ground, then it is possible that at the highest point it will fly horizontally downwind (with speed far greater than the wind speed), and go much further downwind than $v_w \times t$. If you know the horizontal velocity at the top, I would make a correction for that as well, something like $\approx 0.2 \times v_{top} \times T_{flight}$. $\endgroup$
    – Kphysics
    Oct 7, 2019 at 7:07

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