Does hiding parts reduce drags?

[Jestersage]

Why I had asked about whether sweep wings affect drag (only if you flip it upward so it does not produce lift), what about the other way around -- say, hiding wheels or legs?

[FleshJeb]

Only if they retract into a cargo bay, service bay, or fairing. You only have to get them about halfway in though.

For instance:

 

[Jestersage]

Thanks.

[Foxster]

As said, generally no if you mean using the offset tool to move the part inside or behind other parts. 

To get a part shielded in the enclosures mentioned you generally need their centre of mass inside. 

[KerbMav]

Does FAR handle this any different?

If it is still around, I paused for quite a while ...

And still after all these years I dont know how it actually works ... ^^

[fourfa]

In my experience, the 'centroid' or center of mass point needs to be inside the fairing, cargo bay, or service bay.  In the VAB/SPH, use the offset gizmo on the part in question.  The base of the gizmo arrows is the centroid.

At the moment in stock KSP, the old 1.25m structural fuselage and new procedural structural tubes do not shield drag.  But there are Module Manager patches out there to make them shield drag

[Jestersage]

2 minutes ago, fourfa said:

In my experience, the 'centroid' or center of mass point needs to be inside the fairing, cargo bay, or service bay.  In the VAB/SPH, use the offset gizmo on the part in question.  The base of the gizmo arrows is the centroid.

At the moment in stock KSP, the old 1.25m structural fuselage and new procedural structural tubes do not shield drag.  But there are Module Manager patches out there to make them shield drag

Okay, let me be a bit more precise: using breaking ground, we can extend parts within the appearance of a shroud/payload bay. However, does that actually chaneg the drag or not?

[fourfa]

Here's how to find out for sure - press Alt-F12, then select Physics -> Aero -> Show Aero Data in Right-Click Menu.  Then you'll see the extra details like @FleshJeb's photo in comment #1 when you launch to the flight scene.  Launch and gain some speed, and see if the drag is zero or more than zero.  Sometimes it's a bit iterative back and forth between SPH/VAB and flight to get it just right.  But so far I've found it pretty consistent, that if the centroid is inside the bay or fairing, it'll be shielded.  

I haven't started testing Breaking Ground mechanisms that move in and out of closed cargo bays.  It's a good question.

Edited June 6, 2019 by fourfa

[FleshJeb]

5 hours ago, fourfa said:

The base of the gizmo arrows is the centroid.

For the most part. I think I've run into a few exceptions (Wheesley?). I read somewhere that eyeballing the visual centroid of the model is the best bet.

5 minutes ago, fourfa said:

But so far I've found it pretty consistent, that if the centroid is inside the bay or fairing, it'll be shielded.  

Mostly consistent. The experiment I did with that Claw above was originally in a straight-sided 1.25m fairing. I had it very clearly inside, and it was still dragging. What I've read elsewhere is that at least 50% of the visual model should be in (the Claw is rather fat). I suspect it's not quite that complex, but there might be a bit of a fudge-factor for size. I suppose the real test would be trying to obscure an orange tank in a 1.25m fairing. (I have a Work In Progress that's four Mk3 fuselages that I want to obscure with a 3.75+m fairing, so I'll find out soon.)

[Star-Eagle]

On 6/6/2019 at 5:01 PM, fourfa said:

In my experience, the 'centroid' or center of mass point needs to be inside the fairing, cargo bay, or service bay.  In the VAB/SPH, use the offset gizmo on the part in question.  The base of the gizmo arrows is the centroid.

At the moment in stock KSP, the old 1.25m structural fuselage and new procedural structural tubes do not shield drag.  But there are Module Manager patches out there to make them shield drag

I haven't had a chance to play KSP since BG was released, are those new procedural structural tubes part of the DLC?

[FleshJeb]

7 hours ago, Star-Eagle said:

I haven't had a chance to play KSP since BG was released, are those new procedural structural tubes part of the DLC?

From the Making History DLC.

[KerikBalm]

On 6/6/2019 at 11:56 PM, fourfa said:

I haven't started testing Breaking Ground mechanisms that move in and out of closed cargo bays.  It's a good question.

If it starts inside the cargobay, and moves out, it remains shielded, if it starts outside and retracts in, it stays exposed. You have to open and reclose the bay to get this to change.

I found this out when trying to make a paddlewheel powered sub, with a rotor halfway in a cargobay, so that only half of the paddles would be exposed at once, and I could get net thrust instead of just spinning.

It just spun because of that mechanic.