aerodynamic model?

[GoSlash27]

This seems to be a question that would've been answered by now, but if so I can't find it.

Does anybody know the mathematical model that KSP uses for lift and drag? is it similar to real life? Cl*d*v^2=L?

Does drag work the same way as lift?

[Clockwork_werewolf]

I'm not sure about the equation but I do know that the drag equation is a bit too simple. Drag for each part is based on its head on drag if it is flying head on or its angularDrag if going sideways (at least I think these are the .cfg numbers used). This is then multiplied by the parts mass (yea an empty fuel tank has less drag than a full one). It is also worth noting that 3 tanks in a row have as much drag as 3 tanks stacked on top of each other. This is why nose cones are considered useless and only for show and wide asparagus craft can be better than tall thin craft.

Please correct me if I'm wrong but this was how I believe the stock system works. The FAR mod was made to fix this and other problems.

[mhoram]

The exact stock calculation of drag is described in the wiki page about atmosphere.

[Eric S]

Does anybody know the mathematical model that KSP uses for lift and drag? is it similar to real life? Cl*d*v^2=L?

Does drag work the same way as lift?

The aerodynamic model in KSP is at best a gross approximation that was never intended to handle aircraft or anything else beyond a rocket going up and a capsule coming down. It's a placeholder that was created early on in KSP just to get things working. The devs have said in the past that they intend on replacing it at some point, but they haven't commented on it recently, so it's possible that it may slip between the cracks or they may change their minds.

[GoSlash27]

The exact stock calculation of drag is described in the wiki page about atmosphere.

That's exactly what I needed!

Thanks and regards,

-Slashy

[Tortoise]

If you install FAR, itll be similar to real life.

[RoboRay]

Yes, definitely check the FAR mod if you're interesting in any kind of realistic aerodynamics.

[Starwaster]

I'm not sure about the equation but I do know that the drag equation is a bit too simple. Drag for each part is based on its head on drag if it is flying head on or its angularDrag if going sideways (at least I think these are the .cfg numbers used). This is then multiplied by the parts mass (yea an empty fuel tank has less drag than a full one). It is also worth noting that 3 tanks in a row have as much drag as 3 tanks stacked on top of each other. This is why nose cones are considered useless and only for show and wide asparagus craft can be better than tall thin craft.

Please correct me if I'm wrong but this was how I believe the stock system works. The FAR mod was made to fix this and other problems.

nose cones aren't entirely useless. Because they have less drag (stock cones do) they help orient the craft and make it less prone to tumble. But it's not like that's a huge problem with stock aerodynamics so they're offering little utility and imposing substantial mass that eats into your delta-V. If you're really thrifty about your DV then nose cones are wasteful.

something else of interest is that parts apparently reference 'drag type' with choices being default, conical and cylindrical. But I've never seen a difference from changing dragType and I dont know if I'm setting it wrong or if the drag model doesnt actually implement different drag types. (as in maybe someone added those but then stopped working on drag without actually doing anything with that variable)

[Starwaster]

nose cones aren't entirely useless. Because they have less drag (stock cones do) they help orient the craft and make it less prone to tumble. But it's not like that's a huge problem with stock aerodynamics so they're offering little utility and imposing substantial mass that eats into your delta-V. If you're really thrifty about your DV then nose cones are wasteful.

something else of interest is that parts apparently reference 'drag type' with choices being default, conical and cylindrical. But I've never seen a difference from changing dragType and I dont know if I'm setting it wrong or if the drag model doesnt actually implement different drag types. (as in maybe someone added those but then stopped working on drag without actually doing anything with that variable)

Edit: actually I dont think that's correct about angularDrag. It's not sideways drag, it's how much drag is applied when trying to rotate the craft or part.

Aaaand oh oh. This isnt an edit.... I accidentally replied to myself and I see no option to delete this message as I would normally do. Sorry

Edited June 5, 2014 by Starwaster

[mhoram]

I just stumbled on this thread about calculating lift.

[WafflesToo]

The aerodynamic model in KSP is at best a gross approximation that was never intended to handle aircraft or anything else beyond a rocket going up and a capsule coming down... *snip* ..., so it's possible that it may slip between the cracks or they may change their minds.

And it only just barely handles that sometimes.

Pretty much why I think it's important for us to try and put it back on their radar if we can.

[Pecan]

Mods - this isn't a tutorial, is it?