Dumping heat

[The Dark]

I was just pondering this, due to the extreme power outputs of most starships, but just how do vessels in the SW universe dump waste heat? If an ISD is generating 1E25 watts of useful energy (as DW calculated on the power generation page) at 90% efficiency, it would still generate ~1E24 watts of waste heat which would have to be dumped somehow.

Even assuming a perfect radiator with a temperature of 4300K (at which diamond melts), you'd need a radiator with an area of 5.16E16 meters, which seems a bit large to be "hidden" somewhere on an ImpStar.

[Spanky The Dolphin]

Neutrino conversion.

Been there, done that, ate the t-shirt.

[NecronLord]

Yeah, in case you didn't know, there's a masterstroke by Dr. Saxton in the AotC ICS that says SW ships have devices to radiate waste energy as neutrinos instead of heat.

[The Dark]

.....that's a lot of neutrinos. Assuming entirely tau neutrinos of maximum energy, an ISD would give off 3.47E45 neutrinos per second, compared to Sol's 2E38 neutrinos per second, which are split 40/60 among the weak electron neutrinos and the stronger muon and tau neutrinos.

edit: Ah, it's in the ICS. OK, I was wondering where it came from, since I haven't gotten my hands on the AOTC ICS yet.

[NecronLord]

.....that's a lot of neutrinos. Assuming entirely tau neutrinos of maximum energy, an ISD would give off 3.47E45 neutrinos per second, compared to Sol's 2E38 neutrinos per second, which are split 40/60 among the weak electron neutrinos and the stronger muon and tau neutrinos.

Yup. Neutrino sensors are going to be really good at finding Imperial ships.

[Tychu]

I was just pondering this, due to the extreme power outputs of most starships, but just how do vessels in the SW universe dump waste heat? If an ISD is generating 1E25 watts of useful energy (as DW calculated on the power generation page) at 90% efficiency, it would still generate ~1E24 watts of waste heat which would have to be dumped somehow.

Even assuming a perfect radiator with a temperature of 4300K (at which diamond melts), you'd need a radiator with an area of 5.16E16 meters, which seems a bit large to be "hidden" somewhere on an ImpStar.

they're in space. Something tells me when your floating around in 3° K you dont need a "fan" or coolant

[Noble Ire]

I was just pondering this, due to the extreme power outputs of most starships, but just how do vessels in the SW universe dump waste heat? If an ISD is generating 1E25 watts of useful energy (as DW calculated on the power generation page) at 90% efficiency, it would still generate ~1E24 watts of waste heat which would have to be dumped somehow.

Even assuming a perfect radiator with a temperature of 4300K (at which diamond melts), you'd need a radiator with an area of 5.16E16 meters, which seems a bit large to be "hidden" somewhere on an ImpStar.

they're in space. Something tells me when your floating around in 3° K you dont need a "fan" or coolant

Just because something is in space doesn't mean its completely and automatically cooled. Hell, most modern satellites need cooling systems to function (IIRC).

[Adrian Laguna]

It's actually easier to dump heat in an atmosphere than in space. In an atmosphere you can get rid of exess heat through conduction, convection, and radiation. In space, only the last option is available.

[Tychu]

I was just pondering this, due to the extreme power outputs of most starships, but just how do vessels in the SW universe dump waste heat? If an ISD is generating 1E25 watts of useful energy (as DW calculated on the power generation page) at 90% efficiency, it would still generate ~1E24 watts of waste heat which would have to be dumped somehow.

Even assuming a perfect radiator with a temperature of 4300K (at which diamond melts), you'd need a radiator with an area of 5.16E16 meters, which seems a bit large to be "hidden" somewhere on an ImpStar.

they're in space. Something tells me when your floating around in 3° K you dont need a "fan" or coolant

Just because something is in space doesn't mean its completely and automatically cooled. Hell, most modern satellites need cooling systems to function (IIRC).

I do believe that our modern satalites are in the high atmosphere of the planet so its alot warmer relatively speaking. and to point out, its our technology, the Star Wars tech is probally way ahead of us in coolant then us

[Winston Blake]

Even assuming a perfect radiator with a temperature of 4300K (at which diamond melts), you'd need a radiator with an area of 5.16E16 meters, which seems a bit large to be "hidden" somewhere on an ImpStar.

they're in space. Something tells me when your floating around in 3° K you dont need a "fan" or coolant

There may be very little heat in space, but vacuum is a great thermal insulator. A hot object floating in space can't lose energy by conduction or convection, so radiation is the only option and it's pretty slow.

[Agemegos]

Something tells me when your floating around in 3° K you dont need a "fan" or coolant

The effective temperature of space may be 3 K (though I suspect that the interplanetary medium might be a lot hotter than the microwave background), but vacuum has a terrifically low specific heat (zero JK^-1kg^-1). So even though you might lose heat to space even at low temperatures, you don't necessarily do so fast.

There is so little areic power in the microwave background that we can neglect it for all intents and purposes, and just imagine what it takes to radiate 1E24 watts to an infinite heat sink at absolute zero. As Adrian Laguna points out, you can't remove heat by conduction or convection in vacuum, so it all has to go to as radiation.

An ISD has on the order of 200 km^2 of surface area, or 2E8 m^2. So the waste heat flux is on the order of 5E15 Wm^-2. Assume that the ISD is a perfect blackbody radiator (generous) and apply the Stefan-Boltzmann Law for radiation.

j = sT^4

T =(j/s)^1/4

s ~ 5.7E-8 Wm^-2K^-4 (universal constant)

j ~ 5E15 (estimated above)

therefore T ~ 9E20 K

Ninety quadrillion kelvin.

<EDIT> That ought to be

T^4 ~ 8.8 E22 K^4

T ~ 5.4E5 K

Which is 'only' half a million kelvin, and not as hot as the core of a star.

My cheeks are warm, but not that warm. </edit>

The ISD would have to glow very brightly indeed to dump its waste heat to space. But on the bright side (if you will forgive the pun) it would not be inconvenienced by having to radiate to the interior of a star.

[The Dark]

I do believe that our modern satalites are in the high atmosphere of the planet so its alot warmer relatively speaking. and to point out, its our technology, the Star Wars tech is probally way ahead of us in coolant then us

The International Space Station requires almost 6800 square feet of radiator to dump around 100 kilowatts of waste heat. Any contact with atmosphere makes the radiators more efficient, as they can then dump heat through convection or conduction as well as simple radiation.

The Apollo service modules also required multiple sets of radiators, one for environmental control, one for cooling the electrical power system. And this was for a vessel whose electrical system produced an awesome 28 volts. Radiating heat in space is difficult.

[dragon]

Even deep space probes such as New Horizons spacecraft whci is going to plouto needs a cooling system. Geostationary satellite, which are way out of our atmosphere needs a cooling system as well.

Edit. I know alot of people hate technobable in ST but when Saxton uses it they don't complain to much. As Dark shows thats more neutrinos than the sun.

[Ryushikaze]

It's because he keeps the babble to a minimum, and seeing as he is a physicist, has a bit more comprehension of the terms he's bandying about than the ST writers.

[SVPD]

Unless I'm mistaken, neutrinos have momentum, so wouldn't dumping that quantity of neutrinos generate thrust in some direction or other? This was a possible reason for the "klingon flying through the air" in STIII according to the main ste with the NDF theory.

Apparent failure to observe Conservation of Momentum. Conversation of momentum is a fundamental law, like conservation of energy. It affects even the most stupendously massive objects, such as neutron stars (conservation of angular momentum is what causes their high rates of rotation). So why can Captain Kirk fire a one-handed phaser shot in ST3 which carries so much momentum that it can lift a Klingon off his feet and hurl him dozens of feet back through the air? Shouldn't his arm be broken or his shoulder dislocated from the recoil? The simple answer is that the phaser cannot possibly carry that much momentum, because conservation of momentum is a fundamental law. Therefore, the Klingon's movement through the air must not have been due to simple impact physics. Perhaps the chain reaction propagated in such a manner that the stream of neutrinos coming out of his body was largely aimed in one direction (remember that neutrinos do have momentum), so it acted as a jet and drove him backwards. Presumably, phaser particles were ejected from the disrupted nuclei in the other direction, which impacted on deeper tissues. Perhaps the Klingon's body armour somehow contributed to this unusual effect, or it may have been a freakish anomaly (perhaps related to some sort of anomalous space-time condition on the Genesis planet).

[Connor MacLeod]

There's also the possibility of irradiation, since neutrinos are highly penetrative. I got involved in a recent discussion over this topic.. that the neutrino flux of a SW ship (Shields in partticular) would be so intense that it might be lethal to be in close proximity to it.

[Connor MacLeod]

.....that's a lot of neutrinos. Assuming entirely tau neutrinos of maximum energy, an ISD would give off 3.47E45 neutrinos per second, compared to Sol's 2E38 neutrinos per second, which are split 40/60 among the weak electron neutrinos and the stronger muon and tau neutrinos.

edit: Ah, it's in the ICS. OK, I was wondering where it came from, since I haven't gotten my hands on the AOTC ICS yet.

Where'd you pull tha from?

[Agemegos]

Unless I'm mistaken, neutrinos have momentum, so wouldn't dumping that quantity of neutrinos generate thrust in some direction or other?

If they were emitted preferentially in one direction yes. Lots.

But if the neutrinos were emitted anisotropiclly (equally in every direstion) or in an otherwise balanced fashion they thrusts would balance out, leaving a net thrust of zero. But of course when you are talking about such enormous emissions you would need the thrusts balanced with fanatic precious, because the very slightest proportional residue would mean a great deal of momentum.

[Dooey Jo]

therefore T ~ 9E20 K

Ninety quadrillion kelvin.

I get 5.4e5 K

5e15 / 5.7e-8 = ~8.8e22
(8.8e22)^0.25 = ~5.4e5

[Ender]

.....that's a lot of neutrinos. Assuming entirely tau neutrinos of maximum energy, an ISD would give off 3.47E45 neutrinos per second, compared to Sol's 2E38 neutrinos per second, which are split 40/60 among the weak electron neutrinos and the stronger muon and tau neutrinos.

Yup. Neutrino sensors are going to be really good at finding Imperial ships.

Given that they should be able to use their fuel tanks as detectors, and jamming is effective (which wouldn't impact a passive sensor like a neutrino dector) I think their shields might block them.

This is supported by the JAT, marvel comics, and a few other bits.

[Ender]

.....that's a lot of neutrinos. Assuming entirely tau neutrinos of maximum energy, an ISD would give off 3.47E45 neutrinos per second, compared to Sol's 2E38 neutrinos per second, which are split 40/60 among the weak electron neutrinos and the stronger muon and tau neutrinos.

Go on. There has been lengthy discussion of this lately between me and Connor.

[Agemegos]

therefore T ~ 9E20 K

Ninety quadrillion kelvin.

I get 5.4e5 K

5e15 / 5.7e-8 = ~8.8e22
(8.8e22)^0.25 = ~5.4e5

Looks as though I forget to take the fourth root, which is a bit embarrassing.

Fortunately, I'm pretty sure that we can agree that ISDs in the movies are not glowing at even half a million kelvin.

[Spanky The Dolphin]

It's because he keeps the babble to a minimum, and seeing as he is a physicist, has a bit more comprehension of the terms he's bandying about than the ST writers.

That's because it's more descriptive sci-fi tech than technobabble, which is more or less just strings of pure gobbledy-gook nonsense.

[dragon]

It's because he keeps the babble to a minimum, and seeing as he is a physicist, has a bit more comprehension of the terms he's bandying about than the ST writers.

That's because it's more descriptive sci-fi tech than technobabble, which is more or less just strings of pure gobbledy-gook nonsense.

Sure it sounds good, but like a few people posted above there are some glaring draw backs to the method used. And since Saxton is a physicist he it seems he would have thought about that. Ohh well at least it sounds better than the techno wank of ST, which is not that good at all.

[Connor MacLeod]

They're not exactly drawbacks per se, it just requires some unusual assumptions to make sense of really.