Do struts produce drag?

[baldamundo]

I've basically not played between 0.90 and 1.0.4 so not entirely up to date on how the new aerodynamics work. Do struts create drag? And if so, is it dynamically based on their actual aerodynamic profile? And if so, how the hell am I meant to make planes that are structurally sound but also aerodynamic?

EDIT: While I'm here actually, can someone point me to a decent guide for the new aerodynamics? Particularly interested in spaceplane design. I played a bit of FAR in 0.90 so I wonder how many of the considerations from that you now have to bear in mind ?

Edited September 27, 2015 by baldamundo

[Yukon0009]

Along with other physicless parts, they add drag and mass to the root part I believe.

[baldamundo]

Along with other physicless parts, they add drag and mass to the root part I believe.

So is it something like "each strut adds X amount of drag", rather than based sort of dynamically on like their cross-section and stuff?

[Yukon0009]

From what I know yes.

[Alshain]

Not exactly, it adds drag factor, but drag is still based on the cross section of the non-physicsless parent part which is multiplied by the drag factor of the part which had the strut drag factor added to it (or something like that, I don't have the exact formula).

So if the parent part is aerodynamically shielded, it still won't had a significant amount of drag. The physicsless part itself does not need to be shielded, just the parent.

Edited September 26, 2015 by Alshain

[Aegeas]

In Soviet Russia drag produce strut!

[Brainlord Mesomorph]

In Soviet Russia drag produce strut!

Russian crossdressing Kerbals?

[Val]

I've basically not played between 0.90 and 1.0.4 so not entirely up to date on how the new aerodynamics work. Do struts create drag? And if so, is it dynamically based on their actual aerodynamic profile? And if so, how the hell am I meant to make planes that are structurally sound but also aerodynamic?

Yes, the starting node of a strut (and fuel line) produce drag if it is attached to a part that is not shielded by a cargo bay or fairing. And it's quite a lot of drag, relative to it's size. Putting 5 pairs of struts on a spaceplane can neuter it to the point that it doesn't reach orbit. I avoid them as much as possible.

While I'm here actually, can someone point me to a decent guide for the new aerodynamics? Particularly interested in spaceplane design. I played a bit of FAR in 0.90 so I wonder how many of the considerations from that you now have to bear in mind ?

There're some really informative posts in these threads.

• SSTO cookbook. (bunch of "recipes" and some wing info)
  
• "simple" rule to build spaceplanes? (especially from GoSlash27)
  
• On the particulars of drag in 1.0.4 (part comparisons and discussion of drag)
  

[baldamundo]

Thanks, guys! Some really useful info.

Do any mods give you like a drag calculation/estimate when you're in the editor? I'm not seeing an option on MechJeb or Kerbal Engineer. It's just I'd quite like to see quantitatively how much difference my struts are making.

[Red Iron Crown]

NathanKell's excellent AeroGUI can show you summary aero forces while in flight, not aware of any that do so in the VAB.

[surge]

http://pastebin.com/qECY4n0M

Similar to the way Scott Manley once demonstrated how the old massless parts work, this easily made craft will answer your questions - fire, switch to launched craft, and compare trajectories.

(This craft was made in a game with some addons, but hopefully they will be discarded, as no specific parts were used)

[baldamundo]

There're some really informative posts in these threads.

• SSTO cookbook. (bunch of "recipes" and some wing info)
  
• "simple" rule to build spaceplanes? (especially from GoSlash27)
  
• On the particulars of drag in 1.0.4 (part comparisons and discussion of drag)
  

Good grief...reading that thread on drag makes me just want to give up and install FAR...