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Posted by: iceball3
« on: August 29, 2019, 11:46:16 PM »

Hmmm...
What if the stealth module allowed ships equipped with it to picket in dead space without a thermal signature? As long as the ship remains stationary. This would be in addition to it's active sensor effective detected size effect it already has.
Might make it more generally useful, and allow empires to specifically hide ships of size in space depending on how well stealth technology is researched, and incur less mission space occupancy based on the efficiency of the stealth modules as before.
Posted by: SpikeTheHobbitMage
« on: August 10, 2019, 01:57:59 PM »

Alternative technobabble:  The simplest and cheapest TN engines run hot and thermal tech reduces the core temperature and/or recovers exhaust heat to preheat fuel but this requires more complex and expensive hardware.
Posted by: Hazard
« on: August 09, 2019, 07:24:55 AM »

Efficiency and reactor tech have an impact as the more efficient a powerplant or engine is, the less heat it generates per Kw/h.

This is mistaken.

An engine/power plant has a specific power production rating. A ship has a total energy draw. Because energy conversion is not perfect, you lose energy due to inefficiencies in the system, and energy consumed by a ship's system produces waste heat as well, if not necessarily a lot of it.

A power planet rated for 100 MW is going to create 100 MW of exploitable energy presuming 100% efficiency. This would let you then power 100 MW of machinery and equipment on board the spaceship, which must eventually be shed at the same rate to maintain the same temperature. However, if you have a 40% efficiency of energy conversion you can only power 40 MW of machinery and equipment, but you are still producing 100 MW of energy.

Even if 60 MW of that energy is waste heat that cannot be converted, you are still producing and consuming 100 MW of energy.
Posted by: hubgbf
« on: August 07, 2019, 05:43:19 AM »

let's start with some basic assumptions :
  • In space, thermic exchange are made by IR radiation. It is ruled by the Stefan-Boltzmann's law, sigma*€*T^4
  • Due to solar radiation, an object is naturally heated.
  • By insulation, you can slow thermic exchange, but you cannot stop them. You can concentrate heat on a thermal sink for some amount of time if you want.
  • Everything generates heat : human bodies, cooking, recycling Co2, etc...

In conclusion
Even without internal thermic generation, an object in space has a thermic signature.
Without an internal heat sink, you will heat up to a temperature which allow you to radiate enough heat to compensate for the generated heat. And the relation is not a ^2, but a ^4.
Heat generated has a component scaled to the crew (body heat, survival gear, cooking, and so on)
Efficiency and reactor tech have an impact as the more efficient a powerplant or engine is, the less heat it generates per Kw/h.

On a technobable point of view, the reduced thermal tech is some sort of thermal sink coupled with radiator which can store then radiate heat on a directional path, to avoid detection.
But if you consider a base thermal signature, IMHO it must be scaled to the crew and not the size of the ship, as you can cut nearly everything on a ship but life support.

A fun addition will be to have for a limited time the possibility to set a thermal reduction order for ships : the crew get into spacesuit, breath stored oxygen, and eat protein bar. It will reduce efficiency, but will lower the thermal signature, at least for some days...

My 2 cents.



Posted by: Tikigod
« on: August 06, 2019, 06:27:12 PM »

Quote from: Jorgen_CAB link=topic=10312.     msg115696#msg115696 date=1565133105
Quote from: Tikigod link=topic=10312.     msg115695#msg115695 date=1565132367
Quote from: BasileusMaximos link=topic=10312.       msg115604#msg115604 date=1564727565
Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.       

Really depends on the heat being generated internally versus the thickness of the 'insulation layers' before reaching the exterior surface.     

If you have something like a well insulated interior layer, followed by the hull plating and then several layers of armour that is intended to absorb and mitigate thermal energy amongst everything else , then the likely hold of any 'thermal leakage' from idle life support operations is probably close to zero.       If there was ample thermal leakage that any 3rd party could detect heat emitting from entirely contained interior sources then the operational upkeep simply to keep the crew alive would incredibly expensive compared to just designing the various foundation layers acting as insulation more efficiently.      .      .      .       it's space travel after all.       Not high altitude plane travel.       ;)

Well in space there is nothing for the heat to transfer to outside the ship so any heat you absorb into any material must at some point be released, unless you have some sci-fi system for converting heat back into some other form of energy that is stable and can be stored and used again.     

Although it should be entirely possible to stop heat from radiating out into space for a certain time, but at some point you will have to vent it all out.      You could then use such a system to be very stealthy to heat sensors for a certain time period, could be an interesting game mechanic instead of the technology that just reduce the heat signature of a ship.      In general I don't find this technology to be that worthwhile because you can always reduce a ships speed to reduce their heat signature.     .     .      going slow is generally not much of a problem while conductive covert operations.     

Indeed, kind of amended a afterthought based on this point to my previous post.     

I would imagine with the relatively low amount of thermal output needed just to sustain a crew and basic power generation (Assuming ships are using a less intensive form of power generation for undemanding critical systems, and only utilise the main generators for active operations), a efficient design should be able to re-purpose at least a decent amount of its thermal output back into supporting the internal upkeep of the crew.     

A general idea might be compare hull tonnage to armour layers (Lets assume the gradual build-up under idle situations is gradually passed through the hull and directed so it spreads across the entire surface of the exterior armour rather than just gets spat out at one singular point) then exaggerate the end result by a % of time the ship is over its intended deployment time.     

So the ship design would be drafted up to efficiently handle basic idle life support conditions for xxx number of months, within that period of time the thermal output determined directly through the relationship of tonnage versus armour.    So given enough size given away to armour layers you can keep output to zero during idle conditions.    However once a ships deployment time exceeds the designs intended duration the ships thermal output both when idle and when under active operation escalates with each passing month.     

When a ship then returns to a shipyard for maintenance, I suppose the shipyard could also have a process where when performing maintenance on a ship it can take that stored energy from the ships operation that hasn't been bled out and actually use it in some way.    .    .    .     essentially ships could be used as small scale batteries.     Not enough to sustain itself obviously, but with all the military and civilian traffic it's likely to see in a single day probably enough to actually be a relatively efficient approach and lore wise provide additional justification for the basic design efforts over just bleeding everything straight into space and ramping up power generation demands. 
Posted by: Jorgen_CAB
« on: August 06, 2019, 06:11:45 PM »

Quote from: BasileusMaximos link=topic=10312.  msg115604#msg115604 date=1564727565
Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow. 

Really depends on the heat being generated internally versus the thickness of the 'insulation layers' before reaching the exterior surface.

If you have something like a well insulated interior layer, followed by the hull plating and then several layers of armour that is intended to absorb and mitigate thermal energy amongst everything else , then the likely hold of any 'thermal leakage' from idle life support operations is probably close to zero.  If there was ample thermal leakage that any 3rd party could detect heat emitting from entirely contained interior sources then the operational upkeep simply to keep the crew alive would incredibly expensive compared to just designing the various foundation layers acting as insulation more efficiently. . . .  it's space travel after all.  Not high altitude plane travel.  ;)

Well in space there is nothing for the heat to transfer to outside the ship so any heat you absorb into any material must at some point be released, unless you have some sci-fi system for converting heat back into some other form of energy that is stable and can be stored and used again.

Although it should be entirely possible to stop heat from radiating out into space for a certain time, but at some point you will have to vent it all out. You could then use such a system to be very stealthy to heat sensors for a certain time period, could be an interesting game mechanic instead of the technology that just reduce the heat signature of a ship. In general I don't find this technology to be that worthwhile because you can always reduce a ships speed to reduce their heat signature... going slow is generally not much of a problem while conductive covert operations.
Posted by: Tikigod
« on: August 06, 2019, 05:59:27 PM »

Quote from: BasileusMaximos link=topic=10312.    msg115604#msg115604 date=1564727565
Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.   

Really depends on the heat being generated internally versus the thickness of the 'insulation layers' before reaching the exterior surface.   

If you have something like a well insulated interior layer, followed by the hull plating and then several layers of armour that is intended to absorb and mitigate thermal energy amongst everything else , then the likely hold of any 'thermal leakage' from idle life support operations is probably close to zero.    If there was ample thermal leakage that any 3rd party could detect heat emitting from entirely contained interior sources then the operational upkeep simply to keep the crew alive would incredibly expensive compared to just designing the various foundation layers acting as insulation more efficiently so that heat generated internally is contained between the interior and hull before being dispersed back into the interior in some fashion. 

Whilst it would still be a gross simplification of what is being represented, making thermal output when idle tied to hull tonnage against layers of armour present as a basic representation would at least make a bit more sense then the idea of space craft designed so inefficiently that every ship is just bleeding out any noticeable heat into space as part of basic life support operations. 
Posted by: Steve Walmsley
« on: August 02, 2019, 03:00:13 AM »

Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.

Yes, that is what I implemented.
Posted by: Borealis4x
« on: August 02, 2019, 01:32:45 AM »

Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.
Posted by: Alucard
« on: April 12, 2019, 06:24:28 PM »

With the new passive sensor rules, the square root of the signature is already used for detection.

I failed to consider that. Thanks for the clarification :)
Posted by: Steve Walmsley
« on: April 12, 2019, 05:59:33 PM »

I would just really like to suggest using square root of the size of the ship for thermal signature purposes. Eg: Thermal = roof(sqrt(HS)) would result in:

Size            Sqrt    Current
250t           3         0.25 (=0 ??)
1 000t        5         1
10 000t      15       10
25 000t      23       25
50 000t      32       50
100 000t    45       100


I love to play with smaller number of larger warships and there are many detriments to this in Aurora already. This one however seems to be particularly crippling in some scenarios. The square root approach gives a nicer baseline signature for fighters to be detected but does not end up lighting larger ships like a x-mass tree on passive sensors. This both allows larger warships to be used with some amount of stealth as well as prevents fighters abusing being undetectable (less then 1 thermal signature).

I also have to ask... From your Changes post, it seems there is an exploit. Notably if the ship IS moving at very slow speed, the speed formula is used allowing to go below the minimal intended thermal signature. Is this just a bad wording in the post or is this also an error in the coding?

With the new passive sensor rules, the square root of the signature is already used for detection:

http://aurora2.pentarch.org/index.php?topic=8495.msg103085#msg103085

The minimum is the base signature, even when the ship is moving. It is coded that way but I didn't mention it in the post. I'll update it.
Posted by: Alucard
« on: April 12, 2019, 05:31:37 PM »

I would just really like to suggest using square root of the size of the ship for thermal signature purposes. Eg: Thermal = roof(sqrt(HS)) would result in:

Size            Sqrt    Current
250t           3         0.25 (=0 ??)
1 000t        5         1
10 000t      15       10
25 000t      23       25
50 000t      32       50
100 000t    45       100


I love to play with smaller number of larger warships and there are many detriments to this in Aurora already. This one however seems to be particularly crippling in some scenarios. The square root approach gives a nicer baseline signature for fighters to be detected but does not end up lighting larger ships like a x-mass tree on passive sensors. This both allows larger warships to be used with some amount of stealth as well as prevents fighters abusing being undetectable (less then 1 thermal signature).

I also have to ask... From your Changes post, it seems there is an exploit. Notably if the ship IS moving at very slow speed, the speed formula is used allowing to go below the minimal intended thermal signature. Is this just a bad wording in the post or is this also an error in the coding?
Posted by: Shadow
« on: April 12, 2019, 02:11:56 PM »

Option 2, hands down. In essence.

While burning engines would produce a big heat spike, the routine operation of a spacecraft's systems generates heat.

Each vessel should produce a base amount of heat, for starters.
  • If you want more complexity, a portion of that should come from the hull, and then each individual system should pile on that.
  • If you want more, certain systems other than the engines (like weapons) could produce secondary heat spikes.
  • If you want more, each ship could have a heat radiation rate according to the number and quality of radiator components installed. They would control how fast heat comes down to base level after a spike, and after the ship stops burning its engines.
Beyond that, there could be certain components which decrease the base heat signature, like specialized power infrastructure and certain hull coatings. If you want more complexity, you could have heatsink components, which would temporarily absorb large amounts of vessel heat (and therefore reduce the base level) for circumstantial tactical advantage.

Lots of potential here.
Posted by: dukea42
« on: April 09, 2019, 02:39:09 PM »

I was about to post the same as Iceball3, but I realized I am late to the party.

You can make the equation simply Heat Sig = Base + Engines and save you a line of code to get the greater of the two.

The you can later add features as you wish with += Powergens/capacitors, += LaunchingTubes (lasts for whole reload. . . a big negative for single shot pods as they can't quickly cool to hide), -= heatsinks, etc. .
Posted by: Iranon
« on: April 02, 2019, 05:03:05 AM »

Option 2 sounds good as long as it's indeed a floor (I'm always sceptical of mechanics that scream to be played around).

The above sounds interesting, but may be a little too involved. Optional shutdown of nonvital systems, eliminating or reducing the minimum signature while giving one a warm-up period until one can use sensors/weapons/propulsion at full efficiency could be interesting.