Heat Disposal on ships

Bill Woods wrote: But they can get ranges of objects with wedges directly, from gravitic(?) sensors. We've seen people routinely spoofing the strength of the signal and thus the type of ship making it, but not the ship's location. And they can calibrate those sensors every time a ship drops out of hyper, since that has to happen outside the hyper limit.

In real life it's possible to get a rough estimation of the distance of a signal source through analysis of the strength of the signal, but it's ONLY an estimate and may be off by a considerable margin ("confidence" low, medium, high or "Captain, our antennas are being fried!")

I think a single starship getting a "fix" (range and distance) on a grav point source like a wedge using only the ship's passive sensors is probably a little bit of "hand wavium" on RFC's part. But it is his universe and subject to the laws of physics that he lays out.

I would suspect that the sensor antennas on our starship are laid out much like the hydro-acoustic sensors on a 21st century submarine, all along the length of the hull and along a cable that can be extended and retracted from the rear of the ship, thus providing a bit of a baseline where two or more sensors can make up a small "net" and provide some DF location fixing capability.

Read Tom Clancy's Submarine, his explanations are actually pretty good and got him into trouble (again) with the Navy.

Yep. And when you plot all those bearings on a chart,
no 3 of them will meet at the same point

If the crossing points are all within your effective beam-width of each other, you know you've got the bugger nailed. Of course, if that effective width translates to 100km at the target, that still leaves a lot of searching to be done.

robert132 wrote:

Louis R wrote:All of which Himself is quite well aware of, since he's discussed back in the day while explaining why fire-control requires active sensors, but a big deal tends not to be made of it.

As an aside, you can collect accurate range data using passive sensors, but only if you have enough stations arranged correctly with precisely-known baselines between them. And the accuracy is a function of the length of the baselines and the orientation of the formation.

Yep, this is how radio direction finding (among other things) works. The more direction finding sets you have available at known locations picking up and localizing the direction to the transmitter, and plotting out those lines will give you an area in which the transmitter is located. The more tracking lines you have on that specific signal, the more accurate that location should be, i.e. the smaller the area to be searched becomes.

I forget how old the principle is but I think it predates WWI, going back almost to Mr Marconi.

This should work just as well in tracking grav point sources as it does in tracking an HF radio transmission source. The direction finding receiver in both cases is a passive sensor though the network that allows communications between remote sensors and the network hub might itself be subject interception and each transmitter plotted by "the bad guys."

There is one potential method of heat handling (note that I did not say disposal) which might conceivably be used.

Decompressing compressed gasses to absorb heat. In essence something like a modern day heat pump. Now, before people jump on with both feet, it wouldn't be a closed cycle system capable of keeping up with the needs of a ship indefinitely.

Imagine this scenario:

A ship or missile has a lump of some sort of refrigerant gas, compressed with grav tech to such a degree that it borders on becoming neutronium.

As heat is generated in excess of what the ship or missile can radiate safely, the compressed refrigerant is released in order to absorb heat. It does not necessarily need to be released from the ship, though if it is not, as pressure equalizes, it will grow less efficient.

When the ship is capable of maintaining it's temperature without decompressing coolant, it devotes part of it's energy output to recompressing more coolant to regenerate the heat sump.

Missiles have throwaway sumps with no compressor, but any ship with a fusion power plant can regenerate their coolant sump. LACs with fission piles can as well, but it's much less capable, and normally LAC sumps are regenerated by a power feed from the mother ship.

I think that a combination of grav tech and advanced materials science in compressed gas cooling systems could go a long way towards handling heat issues in the Honorverse.

Are you aware of the Joule–Thomson inversion temperature? Hydrogen leaks are great example. A leaking hydrogen line at anything close to room temp (above -80C) doesn't get cold, it gets hot. And eventually boom!

kzt wrote:Are you aware of the Joule–Thomson inversion temperature? Hydrogen leaks are great example. A leaking hydrogen line at anything close to room temp (above -80C) doesn't get cold, it gets hot. And eventually boom!

Eh, from what I just read, hydrogen, helium, and neon are exceptions to the norm, but only at room temperatures. If you get them cold enough though, when they expand, they do actually cool. Now, most ships aren't going to be operating at 40 kelvin, so compressed helium is probably not a good choice of coolant.

However, any coolant we use today would work, and future materials science and grav tech in the Honorverse can probably do much, much better.