Should Ablators block air and heat?

[Arugela]

I have a vehicle that launches with probes on the side of the ship. There are Ablators in front to stop heat from harming them and them overheating. I've noticed they seem to still catch air a bit though. I was wondering if those ablators also stop air from pushing on them?

It's probably more noticeable on high speed reentries. But they definitely still catch air. Is this likely the limit of what the ablators can stop or are they not designed to do that? some of it could be the fuel, gravity, and\or acceleration. How much is normal?

Edit: Once I stopped acceleration this stopped. I'll have to get a pick on reentry to compare it. I know at certain points the survey scanners do get affects on them from heat and air speed.

Edited November 6, 2015 by Arugela

[Foxster]

Nope. You only get occlusion from parts directly connected above.

[Red Iron Crown]

Only things attached by stack nodes or enclosed in a bay or fairing get occluded from the airflow.

[Arugela]

Will it be changed at some point so that objects block air from other objects?

[TheXRuler]

Will it be changed at some point so that objects block air from other objects?

Not sure but FAR does something like this I think

[ForScience6686]

Use a fairing to block. With the setup you have, air must fill the void behind your ablators as you move through the atmosphere causing a lot of drag.

[Snark]

Only things attached by stack nodes or enclosed in a bay or fairing get occluded from the airflow.

Huh. Shortly after 1.0 came out, I made an interplanetary mission that had a big ol' 3.75m heatshield in front, with a skinny spindle attached behind, and some radially attached probes around it that were snug inside its footprint. I coulda sworn that it worked as designed. I should go back and dig it out again and watch it carefully.

One thing that was different between Arugela's ship and mine (not sure if it makes any difference) is that Arugela's ship has heatshields on radially attached assemblies that he's trying to use to protect other radially attached assemblies, whereas mine had a central stack-mounted shield that was trying to protect things radially attached to that stack.

[Red Iron Crown]

Huh. Shortly after 1.0 came out, I made an interplanetary mission that had a big ol' 3.75m heatshield in front, with a skinny spindle attached behind, and some radially attached probes around it that were snug inside its footprint. I coulda sworn that it worked as designed. I should go back and dig it out again and watch it carefully.

It's possible I'm mistaken, now that I think about it. That's the deal for generating drag, but the reentry heating may use a different occlusion method.

[pincushionman]

I think the heating occlusion is a shock-cone-shaped space, instead of the stack-shaped drag occlusion. But I think there are limits to how far out-of-the-box you can go before it breaks.

Edited November 7, 2015 by pincushionman

[NathanKell]

Yep, only drag occlusion is stack-only. Convective occlusion will take location and geometry into account.

[Superfluous J]

Yep, only drag occlusion is stack-only. Convective occlusion will take location and geometry into account.

As a dummy non-dev I'm probably thinking of this wrong, but why not just use the same occlusion method for both? Seems like it'd save some processor cycles, be more predictable in the VAB, and allow more things that "should" be occluded to be occluded?

[Foxster]

As a dummy non-dev I'm probably thinking of this wrong, but why not just use the same occlusion method for both? Seems like it'd save some processor cycles, be more predictable in the VAB, and allow more things that "should" be occluded to be occluded?

Dunno but maybe because with no wind in KSP the air flow is only from the direction of travel, whereas heat can come from atmosphere friction on most parts and from the sun and from engine heat.

[NathanKell]

5thHorseman: the problem is getting the info back from the GPU. Mu looked into that first, of course, but in U4 / DX9 that's slooooow.