Discovery: Air Intakes Help Cool Boosters

[minerman30]

So I was thinking of something I had done a few months earlier, of putting air intakes on ships in an attempt to cool the SRBs.

I decided to experiment to confirm this.

First I made a basic shim sustaining of a core SRB surrounded by eight part-clipped SRBs.

They overheated and exploded, as expected.

Then, I put a ram intake on each of the outside boosters.

The SRBs started overheating later and slower, and they never exploded before running out of fuel.

That's all, just a little trick I found.

[UmbralRaptor]

So, what happens if you attach fins to the boosters? Or struts (EAS-4, octagonal/cubic octagonal, and conventional massive ones)? Or RCS blocks?

>_>

[AmpsterMan]

Minerman, not to burst your bubble, but I feel that is more indicative on how KSP calculates part heat. That is, it is because there is an extra part, be it an intake or otherwise to have the heat dissipitated to.

[lammatt]

part attached = parts to dissipate the heat

you can as well stick some tiny octagonal struts on it

[Whackjob]

Still, that's a pretty awesome find! I wonder if this works for other things. Like... mainsail engines.

[A Fat Pokemon]

Ahh, I remember this. I saw some people placing ladders on boosters and such a while ago to dissipate heat.

[Tw1]

part attached = parts to dissipate the heat

you can as well stick some tiny octagonal struts on it

I was trying to overheat an RT-10 with separatrons stuck to it, and ran into this as a problem. Moved the separatrons.

[minerman30]

Ah, I see, I didn't try to test it with other things. Will do as you said now. I'm assuming struts have this effect as well? (away from KSP right now)

[FlamedSteak]

Sadly my biggest problem is with overheating nukes......space needs more air!

[Captain Sierra]

Sadly my biggest problem is with overheating nukes......space needs more air!

Something doesn't seem right here . . .

[UmbralRaptor]

Sadly my biggest problem is with overheating nukes......space needs more air!

Don't attach them directly to orange tanks?

[I_Killed_Jeb]

Sadly my biggest problem is with overheating nukes......space needs more air!

really? routinely throw 8 nukes onto an orange tank and they never explode from overheating

[LostElement]

Nukes overheat, but never explode. I have burned a long and tedious 13 minute burn. Never exploded.

[FlamedSteak]

I'm always over-cooking them when they're clustered on KW Rocketry tanks.

Actually now that I'm thinking about it, even when they're not clustered....though it seems to be worse whan they are.

So maybe that's the problem......shame, those tanks are real purdy.

Edited January 13, 2014 by FlamedSteak

[Umlüx]

i cluster my nukes every time. mounted on big KRW tanks with the help of some small tanks or B9 engine mounts.

no overheating problems so far.

[Epthelyn]

I'm always over-cooking them when they're clustered on KW Rocketry tanks.

Actually now that I'm thinking about it, even when they're not clustered....though it seems to be worse whan they are.

So maybe that's the problem......shame, those tanks are real purdy.

Unless they're exploding, it doesn't matter. I've never seen nukes go above 80% overheating.

[Seret]

It's a nuclear thermal engine, it's supposed to get really hot.

[Psycix]

That just gave me an idea: For the NERVA's, they should make ISP related to heat level.

This way you cannot use them for unrealistic short burns, and the thrust-nerf can be loosened.

[Sof]

How do you guys manage to actually overheat engines to the extent they explode? I've only had that a few times before I learnt that Mainsail+orange tank was bugged. They fixed that now and I'm honestly having a hard time trying to get any of the engines to explode anymore.

[magnemoe]

My Jool lander back in 0.21 has a lot of overheat issues as the armosphere down in Jool is over 900 degree.

First I tried the 2.5 meter to 4x1.25 meter inteface but it generated to much heat. Shifted to using up to 7 aerospikes on struts this worked well, however again the first version had center engine directly on the tank and it did overheat more than the others so I had to put it on strut too.

it was obviously critical to get as much performance out of the engines as possible to increase TWR.

[boxman]

Still, that's a pretty awesome find! I wonder if this works for other things. Like... mainsail engines.

Do you really need it though? Even they though they still overheat they dont overheat anymore to the point of exploding even during full throttle.

But I guess it might help if you have a bunch of mainsails very close to each other.

[UH60guy]

That just gave me an idea: For the NERVA's, they should make ISP related to heat level.

This way you cannot use them for unrealistic short burns, and the thrust-nerf can be loosened.

I guess it would depend on exactly what's going on inside the engine to make the heat- Remember that ISP is basically a function of engine exhaust velocity. Sure heated particles would vibrate faster, but they're vibrating in all three dimensions while being expelled at 7856 m/s (ISP 800 * 9.82). Not sure that an engine running any hotter could influence how fast the chemical/nuclear/magical reaction expels particles.

What it could influence however, would be the amount of fuel undergoing reaction, and therefore the mass flow rate- basically changing the TWR with how "hot" the engine is running.

[FlamedSteak]

I've had an lv-n overheat so fast that I didn't have time to react before it exploded. It has to be the kw rocketry tanks.

[I_Killed_Jeb]

I guess it would depend on exactly what's going on inside the engine to make the heat- Remember that ISP is basically a function of engine exhaust velocity. Sure heated particles would vibrate faster, but they're vibrating in all three dimensions while being expelled at 7856 m/s (ISP 800 * 9.82). Not sure that an engine running any hotter could influence how fast the chemical/nuclear/magical reaction expels particles.

What it could influence however, would be the amount of fuel undergoing reaction, and therefore the mass flow rate- basically changing the TWR with how "hot" the engine is running.

I think the heat is actually directly related to the particle expulsion speed based on the simple principle that T=avg KE

[Andersenman]

heated particles would vibrate faster, but they're vibrating in all three dimensions while being expelled at 7856 m/s (ISP 800 * 9.82). Not sure that an engine running any hotter could influence how fast the chemical/nuclear/magical reaction expels particles.

That's what the expansion nozzle is for, directing the overall "three-dimensional vibration" (also known as 'pressure') yonderward.