On Friday, 18 November 2022 at 05:54:48 UTC, Robert Woodward wrote:
> A recent thread mentions this happening in John Ringo's _Vorpal Blade_.
> What other titles have submarines in space? The only title that I can
> think of offhand is Harry Harrison's _The Daleth Effect_, but I vaguely
> remember that there are more. What other titles can people think of?

The spaceship in _JAG In Space: A Just Determination_
is "an elongated football shape" (American football
I suppose), if that's any good to you. Shaped for stealth -
if it's coming towards you, anyway. It's described
as a Long Endurance Cruiser.

On Tuesday, November 29, 2022 at 3:48:00 PM UTC-7, Hal Heydt wrote:

> I've thought for some years that the solution would be to develop
> high temperature electronics. There are varieties of vaccuum
> tubes that might work well at Venus-surface temperatures. It
> might be worth seeing if carbon-based semiconductors would work
> at those temperatures.

Silicon carbide is a semiconductor which can work at high temperatures.

Unfortunately, silicon carbide crystals have a high incidence of defects,
and thus discrete transistors and SCRs are made from it... not microprocessors.

John Savard

On 11/29/2022 5:15 PM, Lynn McGuire wrote:
> On 11/24/2022 12:11 PM, Thomas Koenig wrote:
>> pete...@gmail.com <petertrei@gmail.com> schrieb:
>>> On Wednesday, November 23, 2022 at 12:29:56 PM UTC-5,
>>> jack....@gmail.com wrote:
>>
>>> I'd think so. The surface pressure on Venus is about 93 atmospheres,
>>> equivalent to 1km down
>>> In Earths oceans.
>>>
>>> However, I have difficulty imaging a single vessel that could operate
>>> in both environments.
>>
>> Something could be built for the pressure, but temperature would
>> be hard to deal with -  475°C is something.
>>
>> You would need very hot energy source (probably nuclear) to run some
>> sort heating / cooling cycle for the inner spaces to remain cool.
>> We operate gas turbines to above 1000°C, so this is in principle
>> possible.  What we do _not_ do is to operate bearings or electrical
>> wires or.... at that temperature, nor do we know how to.
>>
>> For short stays, an evaporative cooling might work, with the coolant
>> flowing outwards through insulation.  Water could be a possiblity,
>> at least its critical pressure is higher than the ambient pressure
>> on Venus.
>
> Modern gas turbines from GE are running at 1,400 C (2,600 F).  They use
> 100% ceramic combustion pots, power turbine blades, etc.
>    https://www.ge.com/gas-power/products/gas-turbines/lm6000
>
> So, if you build your space ship out of ceramic ...
>
This just in! SpaceX looking for experienced potters for new project....

:P

--
I've done good in this world. Now I'm tired and just want to be a cranky
dirty old man.

Lynn McGuire <lynnmcguire5@gmail.com> schrieb:
> On 11/24/2022 12:11 PM, Thomas Koenig wrote:
>> pete...@gmail.com <petertrei@gmail.com> schrieb:
>>> On Wednesday, November 23, 2022 at 12:29:56 PM UTC-5, jack....@gmail.com wrote:
>>
>>> I'd think so. The surface pressure on Venus is about 93 atmospheres, equivalent to 1km down
>>> In Earths oceans.
>>>
>>> However, I have difficulty imaging a single vessel that could operate in both environments.
>>
>> Something could be built for the pressure, but temperature would
>> be hard to deal with - 475°C is something.
>>
>> You would need very hot energy source (probably nuclear) to run some
>> sort heating / cooling cycle for the inner spaces to remain cool.
>> We operate gas turbines to above 1000°C, so this is in principle
>> possible. What we do _not_ do is to operate bearings or electrical
>> wires or.... at that temperature, nor do we know how to.
>>
>> For short stays, an evaporative cooling might work, with the coolant
>> flowing outwards through insulation. Water could be a possiblity,
>> at least its critical pressure is higher than the ambient pressure
>> on Venus.
>
> Modern gas turbines from GE are running at 1,400 C (2,600 F). They use
> 100% ceramic combustion pots, power turbine blades, etc.
> https://www.ge.com/gas-power/products/gas-turbines/lm6000

Yes, but they have carefully crafted cooling channels in the blades
to shield them from the high combustion temperatures. One reason
why turbine makers are so into 3D printing, it lets them make
cooling channels that would be impossible to manufacture otherwise.

There are, however, some other limitations. Basically, using
organic materials is out at that temperature. This includes
our polymers that cannot withstand Venus surface temperatures.
Wire insulation is going to be a challenge, it would have to
be ceramic only, which makes electric motors or generators...
interesting. The same goes for lubricants for bearings.

On Friday, November 18, 2022 at 12:54:48 AM UTC-5, Robert Woodward wrote:
> A recent thread mentions this happening in John Ringo's _Vorpal Blade_.
> What other titles have submarines in space? The only title that I can
> think of offhand is Harry Harrison's _The Daleth Effect_, but I vaguely
> remember that there are more. What other titles can people think of?
>

Not literally "submarines transported to space", but Glen Cook's
Passage at Arms is pretty much WWII Pacific theater sub warfare,
very closely translated to a space environment. The ships are
"climbers" and are very similar to subs in capabilities, limitations, etc
....in space. The book focuses on an embedded journalist's account
on one such ship.

Tony