Huge Multicannon - Do you wish to see an alternative to the current weapon?

[Stigbob]

The lack of spin-up time on the huge MC is a feature I would not want to lose. I'd be happy to divide bullet throwers into 'machine gun' (like the huge MC but in all sizes) and 'gatling gun' (like the small & medium but in all sizes). The spin-up delay on a large MC is already frustrating enough

I don't mind it the delay plus the huge M/C's slower fire rate means they balance well together on ammo consumption when the huge is corrosive.

 

[Riverside]

I don't mind it the delay plus the huge M/C's slower fire rate means they balance well together on ammo consumption when the huge is corrosive.

You don't mind anything Stigbob, you're a complete pushover

 

[Stigbob]

You don't mind anything Stigbob, you're a complete pushover

I'm solution orientated and do my research pre purchase whilst gravitating to things that I like, which is why I don't bother with things like the whole openvsolo thing.

 

[Julio Montega]

So big old mean huge gatling gun with high ROF balanced by heatspikes,
pellet dmg and armor-penetration? Needs some breach though, shredding modules rocks.

Embrace the "BRRRRRRRRRRRT".

 

[Devari]

If the entire weapon is heating up because it's passively cooled, the entire local ammo pool would be at risk of cook off, caseless or not.

Except that, as I mentioned, in a six-barreled gatling weapon each barrel is only handling 1/6 of the heat build-up that the single barrel would experience. How is this still not obvious?

You aren't taking into account how slow radiative cooling is.

After a fairly short period of firing, that watercooled barrel will be much cooler than any of the six barrels in your radiatively cooled rotary cannon, because any reasonable water cooling system would remove heat at a rate far, far, beyond radiation times six.

Except that if we're talking about a weapon in space, where the ambient temperature is only a few Kelvin, the barrels of the gatling weapon would individually be far cooler for the same ROF.

It's pure heat production vs. heat capacity vs. heat dissipation rate.

Production is tied to ROF. Capacity is tied to the mass of the barrels. Rate is dependent on means and mechanism of cooling.

If we assume the first two are the same, then you are left with how much heat you can remove with water vs. how much heat you can remove with nothing. I can remove a huge amount of heat with some copper tube and a good water pump. Not so much with a couple square meters of metal in a vacuum. Even if the gatling weapon has more total barrel mass, that won't mean much for sustained fire...with next to zero cooling, it will reach saturation very quickly.

If you're starting in a vacuum, from a few Kelvin, then having only 1/6 of the heat build-up per barrel is a massive difference. You can't only consider the effect of vacuum on heat loss without also considering the ambient temperature of space. If one barrel reaches slightly above room temperature, say around 300 k, at a given ROF then six barrels will only each reach 50 k at that same ROF.

Your anecdotal weapons aren't used in space.

Whether they are used in space isn't relevant here, you seem to have completely missed the point that there are real-world weapons that clearly demonstrate that liquid cooling of a firearm barrel is nowhere near as effective as you think it is, otherwise you would see far higher ROF from liquid-cooled, single-barrel weapons than you do from multi-barreled weapons.

They are used on Earth, which has a thick cool layer of air over it, that allows for the cooling from the forced convection of a rotating barrel assembly to dwarf that of radiation by multiple orders of magnitude.

Again, in space you are also at a very low temperature vs. the ambient temperature of around 300 K on earth. You can't only look at the loss of convective cooling in the vacuum of space and not consider the fact that the barrels would require a certain ROF to even reach room temperature.

The weapons aren't cooling, the coolant is. The ship will not allow you to fire any weapons if the coolant is above a certain temperature, because that could result in damage to the weapons, or the coolant loop (which all weapons share).

The weapons still have access to their full power allotment, otherwise the module would shut off.

Which, again, makes no sense because the weapon should still fire and not be "locked out" when the barrel is cold. The idea of a weapon "capacitor" being used to "power" cooling is utter nonsense and the idea that they would all use a single "shared" coolant loop is also nonsense. The WEP capacitor provides energy to all active weapons but there's no reason to think those weapons would all share a single coolant loop simply because they draw power from the WEP capacitor. That would be the worst possible design on a spacecraft to be firing hot beam lasers and use that same coolant loop from the lasers to transfer heat to a cold firearm barrel. It would literally be counter-productive to do that because you would be putting hot "coolant" next to a cold barrel and actually heat up the barrel in the process if it were not firing. If each weapon were individually cooled it would need to have its own separate coolant system.

Revolver cannon, are a thing, as are other mechanisms for powered firing and extraction of single barrel weapons.

Yes, revolver cannons exist, but their only real advantage is shorter spin-up times which is only really relevant in modern jet combat with gun engagement times of under a second. Revolver cannons are far less effective than gatling weapons for sustained fire.

And, as I've repeatedly tried to convey, the ROF advantage from multiple barrels is going to vanish with sustained fire if you don't have any means of removing heat from them.

You do realize that radiative cooling is still going to be relevant, especially if a cannon barrel overheats to the point of becoming red-hot? It is clearly radiating significantly in both the visible and infrared spectrum.

You'll also note that only the barrels, and not the other metal parts of the weapon, are red-hot which his why gatling weapons don't generally have major issues with cook-off compared to single-barrel weapons.

Gatling guns can sustain high ROF in the real world because we have air too cool the barrels with.

Except that, as I've mentioned several times, each barrel is only being used 1/6 of the time which is a massive advantage that allows ROF 6X higher than a single-barrel, liquid-cooled weapon.

You're mostly correct about the advantages of multi-barrel weapons on Earth, but if we had a contest between my watercooled single barrel weapon and your gatling gun in a vacuum, with the same rounds at the same ROF, your weapon would soon have all six (or whatever) of it's barrels glowing white hot while mine was still cold enough to touch.

Your mythical liquid-cooling system is nowhere near as good as you think it would be when comparing real-world weapons operating in Earth-normal environmental conditions. Otherwise, as I've mentioned several times, we would see liquid-cooled, single-barrel autocannons significantly outperforming multi-barrel gatling weapons which they obviously don't. It would also not somehow become orders of magnitude more effective if you're operating a firearm in a vacuum at near absolute zero ambient temperatures because the barrels would already be starting from a much lower temperature and require a certain ROF simply to reach room temperature conditions and be less dependent on cooling to begin with.

 

[Deleted member 110222]

I just wish C2 multis looked as cool as C3/4.

 

[Morbad]

Except that, as I mentioned, in a six-barreled gatling weapon each barrel is only handling 1/6 of the heat build-up that the single barrel would experience. How is this still not obvious?

It's never been in doubt.

It's also not relevant, because six times the radiative cooling rate is going to be dozens, if not hundreds, of times below that you could get with liquid cooling.

Except that if we're talking about a weapon in space, where the ambient temperature is only a few Kelvin

Irrelevant.

The energy needed to heat the barrels several hundred kelvin in a vacuum is not great.

If one barrel reaches slightly above room temperature, say around 300 k, at a given ROF then six barrels will only each reach 50 k at that same ROF.

If that single barrel is one sixth the mass (extremely unlikely), the same heat energy would come close to making it six times the absolute temp.

However, even if you can get six times the shots before the barrel becomes unusably hot, that's still not going to be many shots, in the absence of active cooling.

Whether they are used in space isn't relevant here

Patently false.

you seem to have completely missed the point that they are real-world weapons that clearly demonstrate that liquid cooling of a firearm barrel is nowhere near as effective as you think it is, otherwise you would see far higher ROF from liquid-cooled, single-barrel weapons than you do from multi-barreled weapons.

On a scale of 1 to ten, if a good water cooling system is a 10 and forced air convection is an 8, radiative cooling is going to be a 1.

There is an enormous gulf in cooling rates between spinning a set of barrels through air and through a vacuum.

I am not overstating the effectiveness of water cooling. Water has the highest volumetric heat capacity of any material in existence and nothing without a phase change component (which may very well be boiling the water) can compete with it's ability to remove heat from an object.

You are greatly understating the effectiveness of air cooling and/or exaggerating the effectiveness of radiative cooling.

Yes, revolver cannons exist, but their only real advantage is shorter spin-up times which is only really relevant in modern jet combat with gun engagement times of under a second.

Not their only advantage. Lower weight and power consumption are significant advantages vs. rotary cannon. Higher rates of fire and resistance to jamming/increased reliability are advantages vs. gas/recoil powered single-barrel guns.

You do realize that radiative cooling is still going to be relevant, especially if a cannon barrel overheats to the point of becoming red-hot? It is clearly radiating significantly in both the visible and infrared spectrum.

It will become more relevant as temperatures get higher, but unless you have a weapon that can withstand phenomenal temps, it's never going to be more than a small fraction of the cooling of a weapon that isn't used in a vacuum.

The overwhelming majority of heat leaving the minigun in your image isn't being radiated away, it's being conducted into the air that comes into physical contact with it.

You'll also note that only the barrels, and not the other metal parts of the weapon, are red-hot which his why gatling weapons don't generally have major issues with cook-off compared to single-barrel weapons.

Which wouldn't be the case if the heat had no where to go.

Your mythical liquid-cooling system is nowhere near as good as you think it would be if you're starting in a vacuum at near absolute zero ambient temperature.

If you can come up with a figure for the amount of heat per shot and the material and mass of the barrel, it should be easy to show how a a good water loop could keep a fairly high sustained RoF weapon within a few 10s of C of water temp and the water within a few C of it's freezing point.

You'd also be able to see how a radiatively cooled weapon would rapidly rise to far higher temperatures, no matter how many barrels you gave it (within reason), making it only useful for short bursts, with protracted cooldown periods in-between.

Anyway, you wouldn't want to fire a cannon made out of anything I know of at near absolute zero anyway. This is another advantage of having it attached to a loop...it will never be outside a narrow temperature range, meaning it won't be brittle from cold, suffer excessive wear from heat, have to deal with wild swings of expansion/contraction, nor have any lubricants operate outside their optimal viscosity ranges.

 

[Ozram]

Ok... this might be of use: https://space.stackexchange.com/que...ipated-from-a-satellite-or-any-metal-in-space

 

[Devari]

It's never been in doubt.

It's also not relevant, because six times the radiative cooling rate is going to be dozens, if not hundreds, of times below that you could get with liquid cooling.

That's not true at all, if liquid-cooled autocannons were that efficient they could maintain much higher rates of fire than air-cooled gatling autocannons, which I've already demonstrated is not the case. Liquid cooling is not magical, it still has to obey thermodynamic laws and running liquid next to a hot barrel is not "orders of magnitude" better than a gatling design.

Irrelevant.

The energy needed to heat the barrels several hundred kelvin in a vacuum is not great.

You can't just ignore a nearly 300 degrees Kelvin temperature differential compared to what you experience under Earth-normal conditions. That is a massive difference.

If that single barrel is one sixth the mass (extremely unlikely), the same heat energy would come close to making it six times the absolute temp.

Except that is not how gatling barrels are designed. They are generally very similar in size and weight to the barrels of single-barreled autocannons, you can easily see this by examining a gatling design.

However, even if you can get six times the shots before the barrel becomes unusably hot, that's still not going to be many shots, in the absence of active cooling.

Of course that is going to be a massive difference, that is why you have ROF of upwards of 6000 rpm for six-barreled gatling weapons vs. only around 1000 rpm for a liquid-cooled single-barrel weapon.

Patently false.

You're still not getting the concept. A gatling weapon primarily maintains a high ROF due to spreading the thermal load among multiple barrels, not by conductive cooling. This is especially true for high ROF burst firing where you are firing literally 100 rounds every second for a 6000 rpm gatling weapon.

On a scale of 1 to ten, if a good water cooling system is a 10 and forced air convection is an 8, radiative cooling is going to be a 1.

Citation needed, especially for a coolant loop that would need to operate in space from near absolute zero. You are literally making up numbers that don't have any connection to reality. Your "rating scale" doesn't even have units. Sorry, you need to do better than that.

There is an enormous gulf in cooling rates between spinning a set of barrels through air and through a vacuum.

Not at the high burst ROF of a modern gatling autocannon, the more significant factor will be the number of rounds going through the barrel per second and the only way to reduce that is reduce your ROF (i.e., reduce the rotation speed) or to use a design that has more barrels. Take a look at the picture I posted after 3000 rounds were fired through that weapon, that would have occurred in 30 seconds at a full ROF of 6000 rpm. Are you seriously suggesting that during only 30 seconds of fire in a vacuum vs. Earth-normal atmospheric conditions that there would have been a dramatic difference during that time?

I am not overstating the effectiveness of water cooling. Water has the highest volumetric heat capacity of any material in existence and nothing without a phase change component (which may very well be boiling the water) can compete with it's ability to remove heat from an object.

You are very much overstating the effectiveness of a water-cooled autocannon because you don't understand that the barrel is not fully immersed in a large quantity of water, there is simply a small coolant loop along the outside of the barrel that helps reduce the heat load. The effectiveness of the coolant loop is still limited by conductive heat transfer through the metal of the barrel to the coolant itself and then by the quantity of liquid coolant available. You also don't seem to understand that several designs for water-cooled machineguns and autocannons have existed historically and have almost all been entirely replaced by gatling weapons, with some historical examples such as the 2A7 having water cooling added specifically due to problems with ammunition cook-off in that particular design. Modern air-defence and CIWS systems are all gatling weapons.

You are greatly understating the effectiveness of air cooling and/or exaggerating the effectiveness of radiative cooling.

You are not understanding that a liquid-cooled single-barrel autocannon is still nowhere near competitive with a six-barreled gatling weapon.

Not their only advantage.

Their only meaningful advantage compared to gatling weapons.

Lower weight

Which is a small weight penalty compared to the overall weight of the weapon and aircraft.

and power consumption

Again, quite marginal compared to an aircraft's overall power output, and not an issue with a recoil-operated dual barrel autocannon (GSh-23) or a gas-operated gatling design (GSh-6-23).

are significant advantages vs. rotary cannon.

No, they are marginal advantages. That is why rotary cannons are quite uncommon compared to the widespread use of gatling designs.

Higher rates of fire and resistance to jamming/increased reliability are advantages vs. gas/recoil powered single-barrel guns.

The sustained ROF for a rotary cannon is not competitive with that of gatling weapons, it's simply the shorter spin-up time during a 0.5-1 second engagement window where a rotary cannon offers any significant combat advantage.

It will become more relevant as temperatures get higher, but unless you have a weapon that can withstand phenomenal temps, it's never going to be more than a small fraction of the cooling of a weapon that isn't used in a vacuum.

The overwhelming majority of heat leaving the minigun in your image isn't being radiated away, it's being conducted into the air that comes into physical contact with it.

As I mentioned above, you are arguing that a liquid-cooled autocannon is going to outperform the gatling weapon. Liquid-cooled weapons are simply not as good as you claim.

Which wouldn't be the case if the heat had no where to go.

The heat very much has somewhere to go, it is being radiated into space.

If you can come up with a figure for the amount of heat per shot and the material and mass of the barrel, it should be easy to show how a a good water loop could keep a fairly high sustained RoF weapon within a few 10s of C of water temp and the water within a few C of it's freezing point.

Really? Then show me your calculations. The information you claim to require is easily available if you want to back up your claim.

I already know that liquid-cooled single-barreled autocannons are nowhere near as efficient as you claim they are, otherwise they would predominate over gatling weapons, and they clearly don't. If you have "math" that you think can "prove" over 100 years of military history is somehow "wrong", please show your work or stop making baseless claims. I am pretty certain here that the history of warfare during the entire 20th century and the laws of thermodynamics have already answered this question for you by actually designing coolant loops for autocannon barrels and have found they were less efficient than a gatling design.

You'd also be able to see how a radiatively cooled weapon would rapidly rise to far higher temperatures, no matter how many barrels you gave it (within reason), making it only useful for short bursts, with protracted cooldown periods in-between.

Again, you need to look at real-world firearm designs here which you are trying very hard to ignore despite having been given several examples in my posts.

Anyway, you wouldn't want to fire a cannon made out of anything I know of at near absolute zero anyway. This is another advantage of having it attached to a loop...it will never be outside a narrow temperature range, meaning it won't be brittle from cold, suffer excessive wear from heat, have to deal with wild swings of expansion/contraction, nor have any lubricants operate outside their optimal viscosity ranges.

How exactly do you think your liquid coolant loop is going to work at those temperatures if it's "never outside a narrow temperature range"? That just makes no sense, it has to deal with the same extremes of temperature that the barrels do, otherwise it's going to be counter-productively heating a cold barrel when you pass warm coolant past it.

 

[Ozram]

That's not true at all, if liquid-cooled autocannons were that efficient they could maintain much higher rates of fire than air-cooled gatling autocannons, which I've already demonstrated is not the case. Liquid cooling is not magical, it still has to obey thermodynamic laws and running liquid next to a hot barrel is not "orders of magnitude" better than a gatling design.



You can't just ignore a nearly 300 degrees Kelvin temperature differential compared to what you experience under Earth-normal conditions. That is a massive difference.



Except that is not how gatling barrels are designed. They are generally very similar in size and weight to the barrels of single-barreled autocannons, you can easily see this by examining a gatling design.



Of course that is going to be a massive difference, that is why you have ROF of upwards of 6000 rpm for six-barreled gatling weapons vs. only around 1000 rpm for a liquid-cooled single-barrel weapon.



You're still not getting the concept. A gatling weapon primarily maintains a high ROF due to spreading the thermal load among multiple barrels, not by conductive cooling. This is especially true for high ROF burst firing where you are firing literally 100 rounds every second for a 6000 rpm gatling weapon.



Citation needed, especially for a coolant loop that would need to operate in space from near absolute zero. You are literally making up numbers that don't have any connection to reality. Your "rating scale" doesn't even have units. Sorry, you need to do better than that.



Not at the high burst ROF of a modern gatling autocannon, the more significant factor will be the number of rounds going through the barrel per second and the only way to reduce that is reduce your ROF (i.e., reduce the rotation speed) or to use a design that has more barrels. Take a look at the picture I posted after 3000 rounds were fired through that weapon, that would have occurred in 30 seconds at a full ROF of 6000 rpm. Are you seriously suggesting that during only 30 seconds of fire in a vacuum vs. Earth-normal atmospheric conditions that there would have been a dramatic difference during that time?



You are very much overstating the effectiveness of a water-cooled autocannon because you don't understand that the barrel is not fully immersed in a large quantity of water, there is simply a small coolant loop along the outside of the barrel that helps reduce the heat load. The effectiveness of the coolant loop is still limited by conductive heat transfer through the metal of the barrel to the coolant itself and then by the quantity of liquid coolant available. You also don't seem to understand that several designs for water-cooled machineguns and autocannons have existed historically and have almost all been entirely replaced by gatling weapons, with some historical examples such as the 2A7 having water cooling added specifically due to problems with ammunition cook-off in that particular design. Modern air-defence and CIWS systems are all gatling weapons.



You are not understanding that a liquid-cooled single-barrel autocannon is still nowhere near competitive with a six-barreled gatling weapon.



Their only meaningful advantage compared to gatling weapons.



Which is a small weight penalty compared to the overall weight of the weapon and aircraft.



Again, quite marginal compared to an aircraft's overall power output, and not an issue with a recoil-operated dual barrel autocannon (GSh-23) or a gas-operated gatling design (GSh-6-23).



No, they are marginal advantages. That is why rotary cannons are quite uncommon compared to the widespread use of gatling designs.



The sustained ROF for a rotary cannon is not competitive with that of gatling weapons, it's simply the shorter spin-up time during a 0.5-1 second engagement window where a rotary cannon offers any significant combat advantage.



As I mentioned above, you are arguing that a liquid-cooled autocannon is going to outperform the gatling weapon. Liquid-cooled weapons are simply not as good as you claim.



The heat very much has somewhere to go, it is being radiated into space.



Really? Then show me your calculations. The information you claim to require is easily available if you want to back up your claim.

I already know that liquid-cooled single-barreled autocannons are nowhere near as efficient as you claim they are, otherwise they would predominate over gatling weapons, and they clearly don't. If you have "math" that you think can "prove" over 100 years of military history is somehow "wrong", please show your work or stop making baseless claims. I am pretty certain here that the history of warfare during the entire 20th century and the laws of thermodynamics have already answered this question for you by actually designing coolant loops for autocannon barrels and have found they were less efficient than a gatling design.



Again, you need to look at real-world firearm designs here which you are trying very hard to ignore despite having been giving several examples in my posts.



How exactly do you think your liquid coolant loop is going to work at those temperatures if it's "never outside a narrow temperature range"? That just makes no sense, it has to deal with the same extremes of temperature that the barrels do, otherwise it's going to be counter-productively heating a cold barrel when you pass warm coolant past it.

So my guess is that a proper coolant would work similarly to how it works within a laptop gpu and the use of thermal paste. You can transfer the heat that way, but in order to actually dissipate it, you either be discarding superheated plates (like the in game heat sinks) or you’d be releasing it in the form of radiation (like with the thermal vents on our ships). If it’s to be radiated out, then you’d need some visual protrusions somewhere as that’s what would be radiating out the heat. So, whatever happens you’d need to transfer that heat somewhere before getting rid of it. Shame they haven’t designed more mechanics around this besides the heat sink itself (and silent running vs vents). Oh, looks like they actually made a genuine effort to do so... pretty cool.

 

[Julio Montega]

So my guess is that a proper coolant would work similarly to how it works within a laptop gpu and the use of thermal paste. You can transfer the heat that way, but in order to actually dissipate it, you either be discarding superheated plates (like the in game heat sinks) or you’d be releasing it in the form of radiation (like with the thermal vents on our ships). If it’s to be radiated out, then you’d need some visual protrusions somewhere as that’s what would be radiating out the heat. So, whatever happens you’d need to transfer that heat somewhere before getting rid of it. Shame they haven’t designed more mechanics around this besides the heat sink itself (and silent running vs vents). Oh, looks like they actually made a genuine effort to do so... pretty cool.

Hmm there were more detailled mechanics in the past, which led to stealth meta.
The ship had more modules like the radiators to be toggled in the power tab,
which now are auto toggled by SR.
Heat and stealth surely needs some love.

 

[Ozram]

Hmm there were more detailled mechanics in the past, which led to stealth meta.
The ship had more modules like the radiators to be toggled in the power tab,
which now are auto toggled by SR.
Heat and stealth surely needs some love.

I wish that some mods in game gave a visual change to the ships sort of like ship kits but actually functional, so a thermal mod on a weapon might show little vents that light up as the weapon gets hot from firing or an efficiency mod on the powerplant could add an extra vent to the ship that can be seen etc. or perhaps on certain weapons that don’t look amo based, the amo is actually the coolant, like mini sinks (as they are in Mass Effect) so firing rapid fire burst lasers would also show what looks like superheated spent cartridges flying out (but these would just be the cooling mechanism).

 

[Devari]

So my guess is that a proper coolant would work similarly to how it works within a laptop gpu and the use of thermal paste. You can transfer the heat that way, but in order to actually dissipate it, you either be discarding superheated plates (like the in game heat sinks) or you’d be releasing it in the form of radiation (like with the thermal vents on our ships). If it’s to be radiated out, then you’d need some visual protrusions somewhere as that’s what would be radiating out the heat. So, whatever happens you’d need to transfer that heat somewhere before getting rid of it. Shame they haven’t designed more mechanics around this besides the heat sink itself (and silent running vs vents). Oh, looks like they actually made a genuine effort to do so... pretty cool.

If we take what FD states at "face value" (even when it disregards the laws of physics), they would have us believe that there are small coolant loops that transfer waste heat from our ship weapons (and this coolant loop is somehow "powered" by the WEP capacitor) and a larger central coolant loop that manages total heat from the power plant, thrusters and other systems (and this is what the main heat readout displays). This primary coolant loop is then connected to "heat vents" which radiate the heat into space through radiative cooling. The remainder of the hull is presumably extremely well insulated thermally to the point that there is very little heat transfer directly through the hull when the heat vents are closed, which would be consistent with the use of a type of ceramic layer that has extremely low thermal conductivity. The description of the cooling system from the Elite Dangerous manual is as follows:

"Ships are plumbed with cooling systems that collect heat and transport them to heat vents. These vents feature heat-conductive fins that radiate the heat out into space, allowing the ship to maintain heat levels within sustainable operational ranges."

The question then becomes, how do those heat "vents" get rid of the heat? In a vacuum they are entirely dependent on radiative cooling. Fortunately, that is actually a rather effective way of radiating heat if the temperature of the heat vents and coolant itself is high enough. A good description of this is located here:

http://hyperphysics.phy-astr.gsu.edu...cooltime3.html

"Other heat transfer processes are neglected, namely conduction and convection. For temperatures over 1000 K, this is probably justified. Conduction and convection depend linearly upon temperature, while radiation goes up according to the fourth power."

That means that the hotter an object gets the better it becomes at radiating heat directly into space without being dependent on conductive or convective cooling. Presumably, the coolant loop would operate at high enough temperatures to allow efficient radiative cooling through the heat vents.

Interestingly enough, a red-hot firearm barrel like the barrels in the picture I posted would be at a temperature of around 800 degrees Celcius or around 1100 K, which actually makes it rather effective at radiative cooling once it reaches that high of a temperature.

The use of heat sinks is presumably just a coolant purge where hot coolant is dumped into the heat sink and ejected into space and replaced with a supply of colder coolant stored outside the primary coolant loop. The Elite Dangerous manual describes this as follows:

"A ship fitted with heat sink launchers can temporarily cool down dramatically in a short space of time by activating the launcher, which purges heat from the ship into the heat sink. This heat sink is then ejected into space".

The primary coolant loop, heat vents and heat sinks all generally make sense, as does the hull of the ship being very resistant to high temperatures and being thermally isolated from the coolant system (which is presumably why ships can fly through a star's corona without melting). The method of cooling the weapons and the nonsensical use of the WEP capacitor for "cooling" is the main problem, but this is effectively just a a lazy attempt at "game balance" rather than being from due to a well thought out mechanic for the WEP capacitor (or weapon coolant loops).

 

[Ozram]

If we take what FD states at "face value" (even when it disregards the laws of physics), they would have us believe that there are small coolant loops that transfer waste heat from our ship weapons (and this coolant loop is somehow "powered" by the WEP capacitor) and a larger central coolant loop that manages total heat from the power plant, thrusters and other systems (and this is what the main heat readout displays). This primary coolant loop is then connected to "heat vents" which radiate the heat into space through radiative cooling. The remainder of the hull is presumably extremely well insulated thermally to the point that there is very little heat transfer directly through the hull when the heat vents are closed, which would be consistent with the use of a type of ceramic layer that has extremely low thermal conductivity. The description of the cooling system from the Elite Dangerous manual is as follows:

"Ships are plumbed with cooling systems that collect heat and transport them to heat vents. These vents feature heat-conductive fins that radiate the heat out into space, allowing the ship to maintain heat levels within sustainable operational ranges."

The question then becomes, how do those heat "vents" get rid of the heat? In a vacuum they are entirely dependent on radiative cooling. Fortunately, that is actually a rather effective way of radiating heat if the temperature of the heat vents and coolant itself is high enough. A good description of this is located here:

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/cooltime3.html

"Other heat transfer processes are neglected, namely conduction and convection. For temperatures over 1000 K, this is probably justified. Conduction and convection depend linearly upon temperature, while radiation goes up according to the fourth power."

That means that the hotter an object gets the better it becomes at radiating heat directly into space without being dependent on conductive or convective cooling. Presumably, the coolant loop would operate at high enough temperatures to allow efficient radiative cooling through the heat vents.

Interestingly enough, a red-hot firearm barrel like the barrels in the picture I posted would be at a temperature of around 800 degrees Celcius or around 1100 K, which actually makes it rather effective at radiative cooling once it reaches that high of a temperature.

The use of heat sinks is presumably just a coolant purge where hot coolant is dumped into the heat sink and ejected into space and replaced with a supply of colder coolant stored outside the primary coolant loop. The Elite Dangerous manual describes this as follows:

"A ship fitted with heat sink launchers can temporarily cool down dramatically in a short space of time by activating the launcher, which purges heat from the ship into the heat sink. This heat sink is then ejected into space".

The primary coolant loop, heat vents and heat sinks all generally make sense, as does the hull of the ship being very resistant to high temperatures and being thermally isolated from the coolant system (which is presumably why ships can fly through a star's corona without melting). The method of cooling the weapons and the nonsensical use of the WEP capacitor for "cooling" is the main problem, but this is effectively just a a lazy attempt at "game balance" rather than being from due to a well thought out mechanic for the WEP capacitor (or weapon coolant loops).

Yeah, that’s pretty much how I see it too. I don’t quite find it lazy, but I do wish it were given a bit more love and attention because it’s a. Simple concept and one of the few elements of the game that shouldn’t have to require too much suspension of disbelief.

 

[60mm]

I actually find the C4 MC the most appealing and sensible of the lot. Why any of these guns with such poor ROF would be of a rotary design, and designed to use magazines (?!?!), is beyond me but I don't care as I find the MCs as implemented boring so I don't use them. If it were up to me, rotary MCs would be belt fed, have very high ROF, and Jitter build-up/Thermal Load high enough to effectively limit it to bursts of a couple seconds max.

The only one I'd like to see changed realitiscally would be the C2. The blue housing screams toy!

 

[Devari]

Yeah, that’s pretty much how I see it too. I don’t quite find it lazy, but I do wish it were given a bit more love and attention because it’s a. Simple concept and one of the few elements of the game that shouldn’t have to require too much suspension of disbelief.

Well to be fair the game mechanics around heat management were generally quite consistent up until we had experimental effects and other "magical" weapons such as thermal vent, thermal shock, etc., which basically completely ignored the laws of thermodynamics. Even the multicannon experimental effects such as incendiary rounds were handled in a way that makes zero sense. The most obvious issue here is that incendiary rounds ignite upon impact with their target, they are not "hotter" rounds while they travel through the barrel of the multicannon and should not cause any additional thermal load at all when the weapon is fired. If they were being fired with a larger propellant charge, or at a higher ROF, then sure, I could see the increased thermal load but FD just decided that rounds that are "hot" due to an incendiary effect on impact should somehow also be "hot" to fire as well which makes zero sense. The second major issue here is that incendiary rounds have dramatically higher thermal load but no changes in distributor draw and yet they want us to believe that WEP distributor draw is used to power the weapon cooling loop. If WEP distributor draw were somehow related to cooling demands you would expect incendiary rounds to affect this as well if the WEP capacitor were actually involved in the weapon cooling loop. Instead the mutlicannons with incendiary rounds have zero impact on the weapon cooling loop (i.e., same WEP capacitor draw) and yet somehow magically heats up the primarily loop instead. How exactly is that physically possible?

Really after Engineers and the experimental effects dropped was around the time I stopped viewing Elite as a "space sim" and have been treating it more of a "space combat game" since then. From a gameplay perspective I do understand why weapons like incendiary rounds were nerfed several times for "game balance" reasons but they should have really thought out those game mechanics better before introducing the weapons instead of throwing the laws of thermodynamics into the trash in the process.

 

[Ozram]

Well to be fair the game mechanics around heat management were generally quite consistent up until we had experimental effects and other "magical" weapons such as thermal vent, thermal shock, etc., which basically completely ignored the laws of thermodynamics. Even the multicannon experimental effects such as incendiary rounds were handled in a way that makes zero sense. The most obvious issue here is that incendiary rounds ignite upon impact with their target, they are not "hotter" rounds while they travel through the barrel of the multicannon and should not cause any additional thermal load at all when the weapon is fired. If they were being fired with a larger propellant charge, or at a higher ROF, then sure, I could see the increased thermal load but FD just decided that rounds that are "hot" due to an incendiary effect on impact should somehow also be "hot" to fire as well which makes zero sense. The second major issue here is that incendiary rounds have dramatically higher thermal load but no changes in distributor draw and yet they want us to believe that WEP distributor draw is used to power the weapon cooling loop. If WEP distributor draw were somehow related to cooling demands you would expect incendiary rounds to affect this as well if the WEP capacitor were actually involved in the weapon cooling loop. Instead the mutlicannons with incendiary rounds have zero impact on the weapon cooling loop (i.e., same WEP capacitor draw) and yet somehow magically heats up the primarily loop instead. How exactly is that physically possible?

Really after Engineers and the experimental effects dropped was around the time I stopped viewing Elite as a "space sim" and have been treating it more of a "space combat game" since then. From a gameplay perspective I do understand why weapons like incendiary rounds were nerfed several times for "game balance" reasons but they should have really thought out those game mechanics better before introducing the weapons instead of throwing the laws of thermodynamics into the trash in the process.

Unfortunately... I agree.

 

[rrobes]

Is there an argument about SCIENCE here?

ED only follows SCIENCE when it suits them or they just make stuff up.

If they wanted to make a Gatling gun, they would do using their "rules!?".

I personally would think that the visual/auditory result of a Gatling gun would be rip-roaring a la Expanse. Limit the ROF to bursts, 20-30 rounds.

While we are wishing on a star, move the #4 hardpoints of the Corvette to the front of the canopy so we can see the action.

 

[Morbad]

That's not true at all, if liquid-cooled autocannons were that efficient they could maintain much higher rates of fire than air-cooled gatling autocannons, which I've already demonstrated is not the case. Liquid cooling is not magical, it still has to obey thermodynamic laws and running liquid next to a hot barrel is not "orders of magnitude" better than a gatling design.

You keep comparing liquid cooling of one barrel to forced air convection of several and using the latter as an analog to radiative cooling. This is an enormous fallacy.

You can't just ignore a nearly 300 degrees Kelvin temperature differential compared to what you experience under Earth-normal conditions. That is a massive difference.

You are confusing heat and temperature. It does not take that much heat energy in the scheme of things to raise the temperature of a few hundred kg of metal by 300 degree in the near absence of cooling.

Over the course of sustained firing, yes, that 300K initial temperature differential could likely be ignored.

Except that is not how gatling barrels are designed. They are generally very similar in size and weight to the barrels of single-barreled autocannons, you can easily see this by examining a gatling design.

A hypothetical weapon purpose built for use in a vacuum could not be a passively cooled rotary cannon and would use the heaviest barrel mass budgets would allow. In this case, it could be as massive as the entire barrel assembly of a gatling weapon and still be lighter overall because it wouldn't need as powerful of a motor and the cooling loop for a single barrel would be much simpler.

You're still not getting the concept. A gatling weapon primarily maintains a high ROF due to spreading the thermal load among multiple barrels, not by conductive cooling. This is especially true for high ROF burst firing where you are firing literally 100 rounds every second for a 6000 rpm gatling weapon.

You still aren't comprehending that the total thermal capacity of each barrel is negligible to the total heat produced over the course of sustained firing.

Citation needed, especially for a coolant loop that would need to operate in space from near absolute zero. You are literally making up numbers that don't have any connection to reality. Your "rating scale" doesn't even have units. Sorry, you need to do better than that.

Citation needed? Look up the rate of radiative heat exchange!

https://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html

Generally, the burden of proof is on the one making ludicrous claims. The idea that radiative cooling is more than a small fraction of the cooling of a gatling gun operating on Earth is pure lunacy.

Are you seriously suggesting that during only 30 seconds of fire in a vacuum vs. Earth-normal atmospheric conditions that there would have been a dramatic difference during that time?

Absolutely. After all, you are talking about the heat of firing 3000 rounds in that time.

You are very much overstating the effectiveness of a water-cooled autocannon because you don't understand that the barrel is not fully immersed in a large quantity of water

This is a stupid assertion. I'd have a solid copper barrel sleeve with a helical water channel with several times the surface area of the barrel and I'd pump coolant through it at whatever rate was needed to achieve the temperature differential desired. A motor capable of rapidly accelerating a gatling gun barrel would make one hell of a water pump...we are likely talking many liters per second of fresh, cold, coolant...far more cooling than if you firing the weapon while it was simply submerged in a large quantity of water.

You are not understanding that a liquid-cooled single-barrel autocannon is still nowhere near competitive with a six-barreled gatling weapon.

Not sure where you were able to infer that.

Which is a small weight penalty compared to the overall weight of the weapon and aircraft.

Again, quite marginal compared to an aircraft's overall power output, and not an issue with a recoil-operated dual barrel autocannon (GSh-23) or a gas-operated gatling design (GSh-6-23).

So why are you under the assumption that we wouldn't be using heavier barrels and more capable cooling systems if we we trying to make a weapon capable of sustained firing in a vacuum?

That is why rotary cannons are quite uncommon compared to the widespread use of gatling designs

Gatling = rotary. And revolver cannon are pretty common.

As I mentioned above, you are arguing that a liquid-cooled autocannon is going to outperform the gatling weapon.

In space, versus a radiatively cooled gatling weapon, absolutely.

The heat very much has somewhere to go, it is being radiated into space.

Radiation is a tiny fraction of the cooling of a terrestrial weapon system.

It's not until you start to see it glowing that really significant levels of dissipation through radiation are achieved, and for radiation to be competitive with convection, you'd have to be well past safe operating temperature of what we can currently make barrels out of.

Maybe this would change in the far future, but if we had super alloys capable of retaining their strength while glowing white hot, we'd lose most of the incentive for rotary cannon anyway.

Really? Then show me your calculations. The information you claim to require is easily available if you want to back up your claim.

All you need to know is how much heat is produced, the thermal resistance of the metal between the barrel and the coolant, the temperature of the coolant, and it's flow rate. You could go into a lot more detail, if you had more details of the design, but the basics should suffice for the sake of argument.

I already know that liquid-cooled single-barreled autocannons are nowhere near as efficient as you claim they are

You don't know how crappy radiative cooling is, or how I would cool a space based autocannon.

Again, you need to look at real-world firearm designs here which you are trying very hard to ignore despite having been given several examples in my posts.

I haven't ignored anything.

You need to take a look at real-world firearm designs and understand that they weren't built to rely on radiative cooling.

How exactly do you think your liquid coolant loop is going to work at those temperatures if it's "never outside a narrow temperature range"? That just makes no sense, it has to deal with the same extremes of temperature that the barrels do, otherwise it's going to be counter-productively heating a cold barrel when you pass warm coolant past it.

I think the weapon loop is attached to the primary ship cooling loop (which itself tries to stay within a certain temperature range by moving heat to and extending/opening high-temp/efficiency radiators) by heat exchangers and heatpumps that cool or heat the fluid as necessary to keep it within a tight temperature range (probably the peak density of the coolant).

The heating of overly cold components would be quite intentional and desirable. Cool any of the weapons you've mentioned to near absolute zero and then try to fire them and you'd almost certainly destroy them in the process.

 

[Julio Montega]

So guys, would you like a high ROF alternative?
The discussion of the cooling effectivity is very interesting,
but we don't move forward to finding out if it would suit the game
and your playstyles to have another kinetic variant weapon.