Drag and part shape: Thanks for the help!

[xcorps]

So I understand that certain parts that claim to reduce drag don't actually reduce drag and in fact actually increase it due to the model. I'm thinking specifically of the aerodynamic nose cone, for example.

Does that apply to other parts like adapters? I'm building a lander with the x200 8 (the small rockomax fuel tank) as a base. If I skip on the adapter it saves .1 mass and .2 drag, but what negative effects might it have?

Is just aesthetic?

Edited February 25, 2014 by xcorps
answered

[maccollo]

It's just aesthetics.

You can either build rockets that looks like rockets or you can go for ultimate efficiency, unless you download FAR of course.

[Kruleworld]

I just noticed this. I was going to ask if they actually reduce drag. Would it be better to have drag at (negative) -0.1 or lower? this would mean if your drag is 0.5, it knocks one or two points off that figure when you add a nosecone.

[Deathsoul097]

Problem with that is if you add a bunch of nosecones just spammed around on everything then fly, because of the way the game works, the faster you go, it would add more drag, but it would be negative so you would go even faster. At least, that's how I understand it. Anyway, don't skip out on the nosecones, they actually DO reduce drag in 0.23, albeit a lot less than they should.

[Starwaster]

I just noticed this. I was going to ask if they actually reduce drag. Would it be better to have drag at (negative) -0.1 or lower? this would mean if your drag is 0.5, it knocks one or two points off that figure when you add a nosecone.

I never noticed any real difference in stock drag with or without nosecones. I forget the last time I experimented. It was either .22 or .23. I check every now and then to see if something changed with each version but I forget if I checked for .23

Previously I used an srb with and without the cone. Straight up with sas on. Check apoapsis. Last time I had slightly lowered apoapsis with the cone because of added mass.

That's STOCK drag. FAR drag takes into account nosecones.

[Streetwind]

Yeah, nosecones add mass and add weight, not reduce it. The stock aerodynamic system cannot do such a thing as reduce drag on other parts by putting something in front of it. You could encase a part air-tight with other parts and it would still contribute fully to drag.

However nosecones are said to have a (very minor) stabilizing effect, meaning they allegedly help the rocket go in a straight line. I have no idea if this is true.

[LordFjord]

How exactly is the drag calculated in stock KSP? Do parts built behind each other add up their drag values or is only the most "front" one taken into account (as it should imo, at least when the parts line up perfectly).

Does it actually matter to build aerodynamically plausible planes and rockets? What about all the small parts attached radially (science, batteries, ...)?

Is simply the drag value of all parts summed up?

[Silverchain]

Is simply the drag value of all parts summed up?

I believe it's the mass-adjusted average of all drag value values.

[SSSPutnik]

Yes, mass adjusted and average drag value.

Adding nose cones is a waste of time in the stock game, you need FAR installed to get a benefit.

[Kasuha]

Adding nose cones is a waste of time in the stock game

Not in all cases. It is true for usual lifters. If the rocket is big and heavy, a few nosecones will not make it significantly more stable and will add some weight. The worst idea is to put nosecones on SRBs near the bottom end of the rocket, deep below its center of mass - there they even make the rocket less stable. Reason is, the drag model in stock KSP results in forces moving parts with low drag ahead of CoM and parts with high drag behind the CoM.

But there are cases when adding a nosecone actually helps. Particularly spaceplanes and jet VTOLs can really be made more stable in atmosphere by putting a nosecone or a few on their nose.

[LordFjord]

Thanks for the quick answer. Time to take a look at FAR.

[Starwaster]

Thanks for the quick answer. Time to take a look at FAR.

DO be warned that there is a bit of learning curve both in building and flying rockets with FAR. (In atmo obviously, space doesn't matter)

Narrow front broad aft. Fins are good in back too.

Use fairings definitely.