Thermal testing pt 2: this time it's 1.3.1!

[Archgeek]

After some related discussion earlier this week, I've seen fit to re-do my old 1.1 thermal extremis testing for 1.3.1!  This time I've built a fun little testbed of a nuclear engine, an NCS adapter with only 8 units of LF in it, a z200 battery, an OKTO core, another z200 battery, another NCS adapter with minimal fuel, and another LV-N NTR engine; and once again attached various cooling structures to it.  I've saved those as new craft, and to save time this time, used the in-game hyperedit to toss them into an 88km orbit.

Methodology was again to turn on infinite fuel, burn to an internal temp of 1100K in the probe core, record burn time by comparing MET to MET at start of burn, then cut throttle to see if it can coast cool before the core hits 1200 and explodes.  No need to angle burns to avoid escape or anything this time, thanks to the opposing engines.
Tested where a two pairs each of Gigantor solar arrays, structural girders, radial intakes, airbrakes, wing strakes, tail fins, delta-deluxe winglets, and Big-S spaceplane tails.  As well as a pair of structural fuselages, and Kerbodyne adapters.  Getting more serious, I also tested two pairs each of Large, Small, and Edge static radiator panels, and of course small and medium thermal control systems, ending with a pair of large TCS, and as a bonus, a single large TCS.

On to the results!  Keep in mind these are tests of a tiny, mostly-engine flame satellite with tanks perpetually almost out of fuel, and thus terrible heat sinks.  As such, the given times are to be regarded as impossibly extreme lower bounds.  Of interest, the total internal flux the LV-N produces seems to've doubled since 1.1. (Also, to explain the odd numbers to any flux-accountants, the active radiators would steal internal flux from the engine.  It was indeed producing 14942.53kW for all tests, though.)

I miss imgur album embeds

Edited February 20, 2018 by Archgeek

[LordFerret]

A while back I seem to recall Rapier engines had overheating issues. I found that tacking on some cubic octagonal struts drew and dissipated enough heat to solve my issue. I remember that I'd posted about it, with pictures. That was before radiators existed.

Just about all of my interplanetary transport vehicles use NERVs, clusters of them. It's not uncommon for me to have burn times in excess of 20 minutes... big ship. Radiators are the ticket. I've used several configurations, with success in all but one configuration; Not enough panels to draw the heat, but it didn't explode, it (the ship) just got really really hot.

[Archgeek]

Yup, it's all about getting enough radiative surface area (including the engines themselves) to dissipate the internal heat flux from all of the engines.  I remember that having the first thing connected to an engine be a size larger (mk2 tanks for instance) helps deal with immediate effects as well.

[NewtSoup]

I can't wait to read your results   My tests are not hugely scientific.  

[Starman4308]

When it comes to the Gigantors, I'm a bit unsurprised they have very low thermal conductance. When you're taking probes in towards, say, Moho, then, you don't want them to be conducting much heat inwards towards the main vessel... and with that much surface area exposed to the sun, something tells me they're absorbing a fair chunk of solar thermal flux.

Unless you're taking your vessel so close into the sun that a solar panel in equilibrium will explode, then, you want those to be thermally insulated from the rest of your vessel, essentially in their own little thermal equilibrium at a potentially higher-than-normal temperature.

[Archgeek]

5 hours ago, Starman4308 said:

When it comes to the Gigantors, I'm a bit unsurprised they have very low thermal conductance. When you're taking probes in towards, say, Moho, then, you don't want them to be conducting much heat inwards towards the main vessel... and with that much surface area exposed to the sun, something tells me they're absorbing a fair chunk of solar thermal flux.

Unless you're taking your vessel so close into the sun that a solar panel in equilibrium will explode, then, you want those to be thermally insulated from the rest of your vessel, essentially in their own little thermal equilibrium at a potentially higher-than-normal temperature.

They used to have a passive radiator module on the "back" surface, before they gave us active radiators.  In 1.0 a pair of gigantors could cool a single-nuke ship (probe core, battery, mk1 fuselage, nuke) on infinite fuel to equilibrium.

14 hours ago, Archgeek said:

Album a/tsUx1 will appear when post is submitted

...I see imgur still doesn't like these forums.  Should I present those as a great stonking list of images in a spoiler tag?

[NewtSoup]

I use imgur constantly.

The only thing I have to do when copying the image link is add the file extension of the original picture and it works fine.

[LordFerret]

On 2/18/2018 at 4:05 PM, Archgeek said:

...I see imgur still doesn't like these forums.  Should I present those as a great stonking list of images in a spoiler tag?

Huh? When I click on the link it takes me to the album. Maybe go back and re-edit the text for the link description as "View Album" or something.

[Starman4308]

Thinking about it some more: were you careful to hold the same orientation w.r.t. the Sun? You might be able to control for that a bit better by Hyperediting/cheating your vessel out to a distant heliocentric orbit so as to minimize solar flux.

[qzgy]

1 hour ago, LordFerret said:

Huh? When I click on the link it takes me to the album. Maybe go back and re-edit the text for the link description as "View Album" or something.

I think he means as in Albums still don't imbed.

[Archgeek]

11 hours ago, Starman4308 said:

Thinking about it some more: were you careful to hold the same orientation w.r.t. the Sun? You might be able to control for that a bit better by Hyperediting/cheating your vessel out to a distant heliocentric orbit so as to minimize solar flux.

Nope, the vessels were allowed to drift arbitrarilly, though Set Orbit did seem to set them all at the same starting longitude, so they followed about the same curve of solar exposure.  Also, I did check on that, thinking I might need to control for it in some way, but before firing the engines, incoming rad flux was negligable each time.

11 hours ago, qzgy said:

I think he means as in Albums still don't imbed.

Yup.  My old 1.1 thermo test post had an embed, and it is sad and broken.

[CastleKSide]

Perhaps if you add moar boosters to the album and make it go faster, when it hits this hard forum it will embed just fine.