# Tag Info

13

I am wondering whether there is a mathematical formula that we can use to calculate the drag force without empirical measurements. Yes, much modern rocket design is done with Computational Fluid Dynamics software instead of in wind tunnel testing. can we simply look at the system of one air molecule and the rocket, calculate the instantaneous change in ...

8

It is possible to compute rather than measure the drag on an object. However the answer to the specific technique you suggest: can we simply look at the system of one air molecule and the rocket, calculate the instantaneous change in momentum of the air molecule after collision as the resistive force, and then sum up the forces experienced by all air ...

7

Several things that KSP does not model: The challenges of actually docking two things mechanically together without a handy human such that the plumbing works (leaks have a tendency to go bang) The extra instrumentation required to dock with enough reliability to not risk the mission (need duplicate equipment). Notably for the ISS many craft just take ...

6

There is a mathematical formula, but it requires knowing the pressure and velocity distribution around the surface of the object: $$D=\int_{S_{upper}}\left[-pcos(\theta)+\tau_wsin(\theta)\right]dA +\int_{S_{lower}}\left[psin(\theta)+\tau_wcos(\theta)\right]dA$$ where $S_{lower}$ and $S_{upper}$ refer to the lower and upper surfaces, respectively, and $\theta$...

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