version2_1

Thank you It's quite possible there is a drag spike in the transonic regime, but I simply don't have any formula modeling that - I don't know how FAR calculates stuff really, since i got numbers from the FAR Flight Data Panel that I had problems fitting to my simple drag model: I noticed C_d was changing over time and the referenceArea did dot decrease when I staged radial boosters. I simply used the first formula I could find on wikipedia for the drag, since i studied electrical engineering and have very limited knowledge about aerodynamics So any help in that direction would be appreciated!

I just noticed you have moderation for new user enabled. I did not see that on my first post because the after-post-page telling me went away really fast. I'm happy my post did not vanish and the forum is not broken

Hi there, I tried posting in the General Add-on Affairs Forum, but my thread is not showing up :/ I wanted to write something about my KSP Ascent Simulation Tool and even included screen shots. I tried to post a second time and It told me "duplicate", then reloaded the page really quickly.. But I still cant find my post. Any suggestions?? Greetings version2_1

I recently installed a lot of mods including FAR and Mechjeb2. Mechjeb offers an ascent autopilot and calculates some statistics while ascending from Kerbin: used delta-v, drag losses, gravity losses and steering losses as far as I know. I was wondering how to get an optimal ascent path. Mechjeb seems to have some problems with FAR (drag losses don't seem to work properly). So I decided to write a program to calculate an optimal ascent path for a given rocket. Since c# is my favorite language I implemented my simulation in c#.net. The software is pretty beta right now, but here are some screen shots: (yes I'm still using VS 2010) If someone is interested I will share the source code (and the binary) so you can have a look at it! I did all the calculation to my best knowledge, but there might be still some bugs, but the required delta-v is relatively close to the values I get in KSP, so the general approach seems correct. Also the parameter study yields useful ascent angles: Using the Kerbal X rocket i get: 20° launch angle, 70° at 20km, 90° at 40km. All the angles are relative to the normal, so on the KSP navball the angle will be 90-x. I implemented stages (changing vessel mass), air drag, gravity, and thust (value and angle). Finally here are some code samples showing the formulas I used: // Init Vector2D position = new Vector2D(0, equatorialRadius); // We start "on top of Kerbin" Vector2D velocity = new Vector2D(equatorialRadius * 2 * Math.PI / rotationPeriod, 0); // We get 174,53 m/s for free from the rotation! // Simulation step: double pressure = surfacePressure * Math.Exp(-(position.Length - equatorialRadius) / scaleHeight); //position is a vector, measuring the distance from the center of Kerbin. Vector2D dragForce = -0.5 * area * coefficientDrag * relativeVelocity.Length^2 * relativeVelocity.Normalized * pressure; //relativeVelocity the relative velocity vector in the air flow Vector2D drag = dragForce / mass; Vector2D gravitation = position.Normalized * GM / -Square(position.Length); Vector2D acceleration = thrust + gravitation + drag; velocity = velocity + acceleration * deltaT; position = position + velocity * deltaT; Special thanks to MisterSpock, he helped me implementing the orbital mechanics (calculate AP, Eccentricity) and did some testing!