Launchers and You - Optimization
Sept 26, 2016 22:22:07 GMT
Crazy Tom, domfluff, and 4 more like this
Post by pokington on Sept 26, 2016 22:22:07 GMT
So, I can't be the only one annoyed by the settings of the default drone and missile launchers. It's painful to me that it requires 6.5 MW of power to open a bay door and kick out a drone, so I dived into the module editor and played around with it.
Please see my imgur gallery for the same info as below (click me!).
Here are my discoveries:
1) Ethane is a universally better coolant than water for launchers. It's much lighter, and using ethane instead of water means you cycle way, way faster and therefore produce a lot more heat. Sodium cycles even faster than ethane by about 3x but trims less weight than ethane (so it's still lighter than water).
2) Since you cycle faster, you can downgrade your coolant turbopump -- that can shave a fair amount of weight. Switching to ethane as a coolant and downsizing the turbopump to the exact same cycle rate gives identical performance while saving you 2.79t of mass (almost 30%!).
3) If you're me, you can also lower your inlet coolant temperature to 900K. Why? Because it lets you use aluminum radiators and an aluminum coolant turbopump material (shaving 0.01t mass, woo!). Generally these devices produce so little heat that the low coolant temperature isn't a problem. Three 2m x 1m aluminum radiators weigh slightly less and cost less than equivalent silicon carbide radiators, and are less likely to draw heat-seeking weapons fire to boot.
At this point, it's a straight upgrade to the stock launcher. But does it really need to kick drones out the door at almost 20 miles per hour? Generally I would prefer it cycle faster and more reliably in combat, and consume less power so the ship's other weapons can continue to fire. Honestly, the non-direct-combat performance of these devices is totally irrelevant, and in even if it's forced into direct combat I would rather it cycle quickly and consume less power than have a high launch speed.
As an additional improvement, you can lower the muzzle velocity and mass, and improve cycle speed -- this is done by adjusting the track length, stator depth, and forcer radius.
Reducing track length decreases muzzle velocity, heat production and mass.
Reducing stator depth decreases muzzle velocity and mass, but increases heat production.
Reducing forcer radius decreases muzzle velocity, reload time, but increases heat production.
Track length really doesn't do much in my experience with tweaking it -- I don't particularly care about muzzle velocity so long as it's above, say, 2 m/s, I just minimize it to the point where I'm comfortable.
Stator depth is generally at a happy medium -- too thin and the heat production ramps up to uncomfortable levels, and the mass penalty for it isn't really that big.
Forcer radius can be reduced until you reach the desired reload time for increased heat.
Applying these adjustments to your comfort level gives a launcher that cycles significantly faster, only has a marginally hampered muzzle velocity, and is approximately one tenth the dry mass and cost.
Now you can choose to reduce the power consumption of the launcher -- this will impact launch speed (as well as reducing heat), but also puts less strain on your carriers. Being able to downsize the carrier reactor might be something you are interested in. Dropping it down to 500kW of power consumption allows you to fit two of them on a carrier with the next step down in default reactors.
It turns out that cutting power consumption by a factor of 13 doesn't even halve the launch speed. It drops to a gentle 1.9 m/s, which I bump up to 2.0 m/s by adding a cm to the track.
See the final result below:
Please see my imgur gallery for the same info as below (click me!).
Here are my discoveries:
1) Ethane is a universally better coolant than water for launchers. It's much lighter, and using ethane instead of water means you cycle way, way faster and therefore produce a lot more heat. Sodium cycles even faster than ethane by about 3x but trims less weight than ethane (so it's still lighter than water).
2) Since you cycle faster, you can downgrade your coolant turbopump -- that can shave a fair amount of weight. Switching to ethane as a coolant and downsizing the turbopump to the exact same cycle rate gives identical performance while saving you 2.79t of mass (almost 30%!).
3) If you're me, you can also lower your inlet coolant temperature to 900K. Why? Because it lets you use aluminum radiators and an aluminum coolant turbopump material (shaving 0.01t mass, woo!). Generally these devices produce so little heat that the low coolant temperature isn't a problem. Three 2m x 1m aluminum radiators weigh slightly less and cost less than equivalent silicon carbide radiators, and are less likely to draw heat-seeking weapons fire to boot.
At this point, it's a straight upgrade to the stock launcher. But does it really need to kick drones out the door at almost 20 miles per hour? Generally I would prefer it cycle faster and more reliably in combat, and consume less power so the ship's other weapons can continue to fire. Honestly, the non-direct-combat performance of these devices is totally irrelevant, and in even if it's forced into direct combat I would rather it cycle quickly and consume less power than have a high launch speed.
As an additional improvement, you can lower the muzzle velocity and mass, and improve cycle speed -- this is done by adjusting the track length, stator depth, and forcer radius.
Reducing track length decreases muzzle velocity, heat production and mass.
Reducing stator depth decreases muzzle velocity and mass, but increases heat production.
Reducing forcer radius decreases muzzle velocity, reload time, but increases heat production.
Track length really doesn't do much in my experience with tweaking it -- I don't particularly care about muzzle velocity so long as it's above, say, 2 m/s, I just minimize it to the point where I'm comfortable.
Stator depth is generally at a happy medium -- too thin and the heat production ramps up to uncomfortable levels, and the mass penalty for it isn't really that big.
Forcer radius can be reduced until you reach the desired reload time for increased heat.
Applying these adjustments to your comfort level gives a launcher that cycles significantly faster, only has a marginally hampered muzzle velocity, and is approximately one tenth the dry mass and cost.
Now you can choose to reduce the power consumption of the launcher -- this will impact launch speed (as well as reducing heat), but also puts less strain on your carriers. Being able to downsize the carrier reactor might be something you are interested in. Dropping it down to 500kW of power consumption allows you to fit two of them on a carrier with the next step down in default reactors.
It turns out that cutting power consumption by a factor of 13 doesn't even halve the launch speed. It drops to a gentle 1.9 m/s, which I bump up to 2.0 m/s by adding a cm to the track.
See the final result below:
