Traveller as a Spaceship Modeling Hobby

Discuss the Traveller RPG and its many settings
Linwood
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Re: Traveller as a Spaceship Modeling Hobby

Postby Linwood » Wed Nov 07, 2018 10:57 am

What about an improved thermoelectric generator? TEG efficiencies are very low at present but with technological improvements maybe they could draw off a portion of waste heat and put it to use to lessen needed radiator capacity.
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Re: Traveller as a Spaceship Modeling Hobby

Postby Pyromancer » Wed Nov 07, 2018 11:35 am

Linwood wrote:
Wed Nov 07, 2018 10:57 am
What about an improved thermoelectric generator? TEG efficiencies are very low at present but with technological improvements maybe they could draw off a portion of waste heat and put it to use to lessen needed radiator capacity.
You have to look at the efficiency of the total system. I'm no expert in thermodynamics, but intuitively, adding a low (or even medium) efficiency stage to a high efficiency heat engine (like a TL12 fusion reactor) won't help much, if at all.
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Re: Traveller as a Spaceship Modeling Hobby

Postby AnotherDilbert » Wed Nov 07, 2018 1:46 pm

Adding a TEG would not really decrease the need for radiators, but possibly decrease the main fusion reactor a bit. Nearly all energy produced or used onboard will end up as motion or waste heat, so even if we can reuse some of the waste heat, it will just end up as waste heat again. Energy is never created or destroyed, just transformed from one form to another (Conservation of Energy). Sooner or later all energy we use end up as waste heat.

The problem is that it is very difficult to extract usable energy from waste heat, it already has very high entropy (disorder) and entropy can't decrease (2nd Law of Thermodynamics). Concentrated heat, such as from a reactor has lower entropy, and we can turn some of it into low entropy (ordered, usable) energy while turning the rest of it into very high entropy (disordered, unusable) energy, i.e waste heat.
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Re: Traveller as a Spaceship Modeling Hobby

Postby locarno24 » Wed Nov 07, 2018 1:58 pm

AnotherDilbert wrote:
Wed Nov 07, 2018 1:46 pm
Adding a TEG would not really decrease the need for radiators, but possibly decrease the main fusion reactor a bit. Nearly all energy produced or used onboard will end up as motion or waste heat, so even if we can reuse some of the waste heat, it will just end up as waste heat again. Energy is never created or destroyed, just transformed from one form to another (Conservation of Energy). Sooner or later all energy we use end up as waste heat.

The problem is that it is very difficult to extract usable energy from waste heat, it already has very high entropy (disorder) and entropy can't decrease (2nd Law of Thermodynamics). Concentrated heat, such as from a reactor has lower entropy, and we can turn some of it into low entropy (ordered, usable) energy while turning the rest of it into very high entropy (disordered, unusable) energy, i.e waste heat.
This.
But yes, MJ.

Didn't see the value listed for the scout - "A Scout has a fusion reactor producing 500 MW electrical power, or perhaps 1000 MW heat (according to CT). "
1000 MW is 1000 MJ per second. That's still going to eat lhyd really, really fast if you're using it as discard-able coolant...given that 40dTons was supposed to be "one jump-2 (20 dTons) and ten weeks of operation" for a Type S, that doesn't seem to add up.
Understand that I'm not advocating violence.
I'm just saying that it's highly effective and I strongly recommend using it.
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Re: Traveller as a Spaceship Modeling Hobby

Postby AnotherDilbert » Thu Nov 08, 2018 1:52 pm

locarno24 wrote: That's still going to eat lhyd really, really fast if you're using it as discard-able coolant...given that 40dTons was supposed to be "one jump-2 (20 dTons) and ten weeks of operation" for a Type S, that doesn't seem to add up.
Agreed, we don't have even remotely enough "fuel" to use as coolant.

And not even remotely enough radiators.
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Re: Traveller as a Spaceship Modeling Hobby

Postby steve98052 » Thu Nov 08, 2018 4:10 pm

It might be an interesting exercise to design ships that actually have enough radiators. Maybe the actual power plants are small "Mr Fusion" type things, and the dtons required for a ship are storage for folded up radiators.

This would be an exercise in variant rules, obviously.

It would also make atmospheric craft vastly more capable than space vehicles, because they can dump heat into the air.
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Re: Traveller as a Spaceship Modeling Hobby

Postby Condottiere » Fri Nov 09, 2018 1:47 am

Condottiere wrote:
Tue Nov 06, 2018 8:29 pm
Image

Substitute heat sink for reactor, and manual flush for control rods.

Image
To be more specific, the fuel tanks would substitute for the cooling towers, while all that unprocessed onboard heat is directed to the boiler.

The plus side would be that you don't have to worry about radiation, and in theory, you'd have perpetual energy.
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Re: Traveller as a Spaceship Modeling Hobby

Postby Sigtrygg » Fri Nov 09, 2018 5:05 pm

You do know that is physically impossible? 2nd law of thermodynamics and all that.
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Re: Traveller as a Spaceship Modeling Hobby

Postby Bardicheart » Fri Nov 09, 2018 7:20 pm

To answer the original topic, for me right now ship design absolutely is its own mini hobby. Since I moved a few years back I haven't had a regular gaming group so most of what I do is just for my own amusement. Of late I've been tinkering with ideas for ship design both for my amusement, but also as inspiration for 3D modelling.

Reading back over the thread I thought Epicenter raised some very valid points. Ironically, I've heard some of the same from friends in the FX industry regarding concepts for space ships for TV and movies. Some of them have gone to the point of talking more to people at NASA and Navy personnel to get a better understanding of how things are done and why in the real world and how that might translate into space. But I don't think necessarily all of Epicenter's points would or should be applied universally. Military ships should have lots of bulkheads, compartmentalization, etc. Same for scout ships and research vessels. But merchant vessels, passenger liners and pleasure craft (yachts) might have considerably less, and in the real world they often do (sometimes with disastrous results, but people don't want the inconvenience of all those doors and hatches even it if eventually gets them killed, human nature). So some things on his list might be conditional depending on the type of vessel (or maybe that luxury liner or yacht does have bulkheads but they're more expensive because they have to be both larger and not visible as what they are while still being able to slam shut automatically in an emergency, that might be an interesting ship's option). I also think some of what he mentions could easily be included in existing ship design, but its just not noted either in the design rules or deck plans. How much storage is there really? Does a ship's corridor look like something off the ST:NG Enterprise or more like this:

Image

With storage space everywhere, spread out all over the ship in various compartments. In the past people didn't give it much thought, back in the 70s, 80s and 90s we didn't know to give it much thought but with the changing times, being able to see live streams from the ISS, our awareness has changed and these question become more relevant. Not just in gaming but in movies and TV and written fiction, people want what seems realistic and the bar for that has been considerably raised.

Anyway, to answer the OP, yeah at this point ship design is kind of the main part of the hobby for me now. I've always enjoyed tinkering with ship designs and I'd like to think I've gotten a lil bit more realistic with them over the years but there's always something you didn't think of. Maybe at some point I should share some of what I've come up with.
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Re: Traveller as a Spaceship Modeling Hobby

Postby Condottiere » Sun Nov 11, 2018 12:22 pm

That heat has to go somewhere, and dumping it back into the boiler seems the most useful use of it.

If less heat is recycled than produced, that works out quite well as well.

As regards radiators, try string theory, or cable, by trailing cables a couple of miles connected to nets that dispose of that heat.
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Re: Traveller as a Spaceship Modeling Hobby

Postby Linwood » Sun Nov 11, 2018 2:20 pm

Which leads to the thought that one of the first things a crew might do after exiting jumpspace is unfurl the cooling net. Unless we can assume ships can dump waste heat while in jumpspace?
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Re: Traveller as a Spaceship Modeling Hobby

Postby AnotherDilbert » Sun Nov 11, 2018 6:59 pm

If we could not dump heat in jump space, we would cook. Heat sinks that could soak up 1 GW for a week would be rather magical.
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Re: Traveller as a Spaceship Modeling Hobby

Postby WingedCat » Mon Nov 12, 2018 6:22 am

paltrysum wrote:
Mon Oct 29, 2018 7:28 pm
Always consider landing gear with your design if you intend to land your ship.
An aesthetic touch, but one that so many people miss.
paltrysum wrote:
Mon Oct 29, 2018 7:28 pm
Sensors are traditionally placed in the nose of the ship along with the avionics.
I try to spread my sensors around the ship, to let the whole ship serve as a distributed array of sensors - even those that don't explicitly have that upgrade (which, perhaps, just don't have enough sensors to get the mechanical benefit).
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Re: Traveller as a Spaceship Modeling Hobby

Postby Condottiere » Mon Nov 12, 2018 6:28 am

Cables and nets don't take up much actual volume when unfurled.
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Re: Traveller as a Spaceship Modeling Hobby

Postby AndrewW » Mon Nov 12, 2018 7:37 am

WingedCat wrote:
Mon Nov 12, 2018 6:22 am
I try to spread my sensors around the ship, to let the whole ship serve as a distributed array of sensors - even those that don't explicitly have that upgrade (which, perhaps, just don't have enough sensors to get the mechanical benefit).
I figure the equipment for the sensors is used for processing, the sensors themselves are embedded in the hull and feed the information into it for processing.
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Re: Traveller as a Spaceship Modeling Hobby

Postby locarno24 » Mon Nov 12, 2018 8:38 am

WingedCat wrote:
Mon Nov 12, 2018 6:22 am
I try to spread my sensors around the ship, to let the whole ship serve as a distributed array of sensors - even those that don't explicitly have that upgrade (which, perhaps, just don't have enough sensors to get the mechanical benefit).
I think it's a case of how far apart the sensors can be. Distributed sensors essentially act as an interferometry baseline, like multiple orbital telescopes - Note that the non-capital ship equivalent of 'extended arrays' which basically take the same sensors and put them on the end of swing-out booms for ships which aren't big enough to get the sensors that far apart naturally.
Understand that I'm not advocating violence.
I'm just saying that it's highly effective and I strongly recommend using it.

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