aerozine-50

Thank you very much for your help. I remember reading your post before making this thread. One thing I haven't understood well is if bodies in KSP generate lift too (like cylindrcal bodies of rockets). I think there's a bit of confusion here, but you pointed out I, indeed, forgot the squared term. I derived that formula from the one you wrote in your thread: In a 2D plane you could rewrite that formula as (by looking at the image, assuming a dragcube with only +x and +y faces) D = ½ ρ ( V² cos2(α) Ax Cd,x + V² sin2(α) Ay Cd,y ) = ½ ρ V² (cos2(α) Ax Cd,x + sin2(α) Ay Cd,y) Regarding real life, in my aerodynamics course I never heard about a sine-squared tendency of Cd with respect to angle of attack. For airfoils the behaviour is pseudo-polynomial, similar to x2 . For instance for the NACA 0015: Other arifoils may have a low near-constant drag region (called laminar bucket) followed by a steep increase of drag outside of it. While induced drag (which afaik is not modeled by stock aerodynamics, but Ferram does) is proportional to the square of the generated lift.

Hello, I've been planning to write a program to optimize ascent profiles but without running KSP. My idea is to write a genetic algrorithm, similar to the work of CheersKevin ([YT Link]), but it should simulate the dynamic equations without running KSP so the optimization can be faster. While KSP provides straightfoward modeling of the propulsion and masses, I can't wrap my head around the aerodynamics. In order to be able to properly simulate the aerodynamic forces, I need to model both drag (CD) and lift (CL) From what I've read it uses this "cubedrag" modeling where each component has a drag area (CdA) for each direction. The full drag area is a weighted sum of all the faces depending on the relative wind. For instance in a 2D plane, if the relative wind is at 2 degrees of incidence you would have something like: CdA = CdAx cos(2°) + CdAy sin(2°). While this makes kinda sense, I am not sure if the game just accounts for the drag areas that are exposed to the air, or all of them (so including the opposite faces). This is important because in Physics.cfg you can find a set of curves used to correct the aerodynamic data, and some involve the drag areas of faces opposite of the flow. I've tried to reverse-engineer the code in Kerbal Wind Tunnel mod to better understand the stock aerodynamics, but I'm still confused. It would be very helpful if you could also explain me the lift model. While the drag data is in the parts file, I can't find anything about the lift data. Thank you very much for your help.