CT Only: Book2 Maneuver/Evade idea

[kilemall]

You're missing the real world constraint of inefficiency.
You're also making a canonically false assumption of 1 tonnes mass per Td; in looking at Striker, MT, TNE & T4 designs, mass is closer to 10 tonnes per Td. Knocks it up a factor of 10.

Note that the fuel rates given would be something astonishingly low recovery by book rates. 1 tonne of Hydrogen should be enough for multiple megawatt months.

Ty Beard and a couple others have done the math, and either the fuel is used mostly (around 98%) as working fluid rather than actual power, or the 250 MW is a recovery of under 10% of energy released... or both.

I think it’s simultaneously expelling heat and providing reaction mass to a ship that is massing a few kgs with a maneuver drive that neutralizes most of the mass.

 

[Tobias]

An Idea to consider about Book2’s ship combat computer program Maneuver/Evade.

The Mayday version of Maneuver/Evade requires 1g of thrust to be expended when using them.

Maneuver/Evade uses a fraction of Pilot’s skill as the source of the defensive DM.

Thus using extra thrust above the “required” 1g effectively adds 1 to 1 to the pilot’s effective skill before the fraction is applied.

In essence adding an Agility mechanic to book2. Making maneuver rating matter more.

RAW, this is a sensible idea because among other things it enables even lower levels of Pilot skill to make a difference.

 

[Straybow]

I did, then did the calculation from the required Joules... In traveller terms 1 ton at 1 g is 10,000 joules or post conversion 10 kilowatts

So, is the 10kJ "required Joules" for 1 ton mass at 1G, or 1 Td at 1G? Is 1 Td five tons (rough conversion to British Register Tons), or ten tons (your assumption for 100 Td = 1000 tons), or 14.07 tons (water displacement), or 310 tons (packed with Osmium)?

I'm also curious: where did you get the "required Joules" figure? Not CT, nor do I see it in MT. My access to TNE is non-searchable images.

10kW for 1 ton at 1 G is only 13.4 HP/ton... no, that figure is wildly off. The M1 Abrams is 20 HP/ton (50% higher), and I'm absolutely certain that it can't do 1G acceleration (0-60mph in 2.75 sec).

 

[kilemall]

Not to get too much off on a tangent, but how much of a difference do you think there would be in this effect between a beam/pulse laser operating in an atmosphere vs. one in a vacuum?

In game terms this was covered by CT Striker- a factor of 1000.

I did the work in a CT thread, effectively this yields the 1EP laser results from LBB2 ranges transposed to the Striker effective/long/extreme paradigm.

 

[infojunky]

So, is the 10kJ "required Joules" for 1 ton mass at 1G, or 1 Td at 1G? Is 1 Td five tons (rough conversion to British Register Tons), or ten tons (your assumption for 100 Td = 1000 tons), or 14.07 tons (water displacement), or 310 tons (packed with Osmium)?

I'm also curious: where did you get the "required Joules" figure? Not CT, nor do I see it in MT. My access to TNE is non-searchable images.

Ok, some baseline Traveller centric assumptions for conversations along these lines.

• 1g = 10 m/s^2
• Mass of starships is a assumed 10 metric tones per dTons.

With those one must remember 1 joule/sec is equivalent to 1 watt.

Thus to move 1 dTon at 1g you need 10,000 joules or 10kw
From there we see that it requires 1Mw to move a 100dTon at 1g.

Remember 1hp is around 745 joules/sec...

 

[Straybow]

10kW for 1 ton at 1 G is only 13.4 HP/ton... no, that figure is wildly off. The M1 Abrams is 20 HP/ton (50% higher), and I'm absolutely certain that it can't do 1G acceleration (0-60mph in 2.75 sec).

Ok, some baseline Traveller centric assumptions for conversations along these lines.

• 1g = 10 m/s^2
• Mass of starships is a assumed 10 metric tones per dTons.

With those one must remember 1 joule/sec is equivalent to 1 watt.

Thus to move 1 dTon at 1g you need 10,000 joules or 10kw
From there we see that it requires 1Mw to move a 100dTon at 1g.

Remember 1hp is around 745 joules/sec...

Yes, that's where I got 10kW = 13.4 HP. 10kW per ton can't do 1G. You have 10 tons, or 1kW/ton doing 1G. That's a paltry 1.34 HP/ton. I think the top speed would be somewhere around a fast walk.

What's the HP (or kW) of your car? How much does it weigh? Can it do 1G = 0-60mph in 2.75 sec?
My minivan is 283 HP. It weighs about 2 tons with just the driver. It can do 0-60 in 6-7 sec if you don't mind the wear on tires and transmission (strongly not recommended as the transmission has 1st and 2nd gear made of composite instead of metal). 0-60mph in 5.5 sec is ½G.

Hmmm, your scientific unit analysis is a bit off.
10 tons × 10 m/s² = 100kN, so you're off by a factor of 10 and in the wrong units.

 

[kilemall]

Ok, some baseline Traveller centric assumptions for conversations along these lines.

• 1g = 10 m/s^2
• Mass of starships is a assumed 10 metric tones per dTons.

With those one must remember 1 joule/sec is equivalent to 1 watt.

Thus to move 1 dTon at 1g you need 10,000 joules or 10kw
From there we see that it requires 1Mw to move a 100dTon at 1g.

Remember 1hp is around 745 joules/sec...

Umm that sort of figure may explain Traveller missiles nicely, but you are saying a 30 HP ‘motor’ moves 1000 tons at 2G or so.

That doesn’t pass the smell test.

 

[Krikkitone]

How much power (W or kW or HP) is needed to accelerate 1 ton at 1 G in a frictionless vacuum will depend on how fast that 1 ton is moving.

Accelerating 10 metric tons (10^4 kg) at 1 G (10 m/s^2) with 10 kw (10^4J/s) will work as long as it is moving 0.1 m/s or less

 

[infojunky]

Yes, that's where I got 10kW = 13.4 HP. 10kW per ton can't do 1G. You have 10 tons, or 1kW/ton doing 1G. That's a paltry 1.34 HP/ton. I think the top speed would be somewhere around a fast walk.

Oh... I see your problem...

The 10kw is to move 1 ton at 1g. i.e. 13.4hp to move that ton 10 meters in a second.

Which is more than reasonable.

What's the HP (or kW) of your car? How much does it weigh? Can it do 1G = 0-60mph in 2.75 sec?
My minivan is 283 HP. It weighs about 2 tons with just the driver. It can do 0-60 in 6-7 sec if you don't mind the wear on tires and transmission (strongly not recommended as the transmission has 1st and 2nd gear made of composite instead of metal). 0-60mph in 5.5 sec is ½G.

Ok, this is a an apples and oranges situation here. In that at best automotive horsepower only 30% of that energy goes to move the the vehicle. The rest is lost to inefficiencies in the system

Whereas, The numbers I used are based on thrust in a frictionless model.

Hmmm, your scientific unit analysis is a bit off.
10 tons × 10 m/s² = 100kN, so you're off by a factor of 10 and in the wrong units.

Well, I did shortcut the specific unit, in that joules/sec is the equivalent a newton, but since I factored out the time aspect that it a minor quibble.

And the 10kw per ton is the base I worked from.

Though I did step up to the 100dton hull at 1000 metric tons at 1g to get the EP equivalent of 1Mw. (note, 1 EP per Book5 is what is required to move a 100 dTon hull at 1g)

 

[infojunky]

How much power (W or kW or HP) is needed to accelerate 1 ton at 1 G in a frictionless vacuum will depend on how fast that 1 ton is moving.

Accelerating 10 metric tons (10^4 kg) at 1 G (10 m/s^2) with 10 kw (10^4J/s) will work as long as it is moving 0.1 m/s or less

Err!?!

Please note I did note include Tau in my calculations.

In that I am working from Acceleration not speed. As such for a given force and mass, Acceleration will remain constant.

 

[Krikkitone]

Err!?!

Please note I did note include Tau in my calculations.

In that I am working from Acceleration not speed. As such for a given force and mass, Acceleration will remain constant.

Except Power(kW,HP) =/=Force(N)

 

[Tobias]

How much power (W or kW or HP) is needed to accelerate 1 ton at 1 G in a frictionless vacuum will depend on how fast that 1 ton is moving.

Accelerating 10 metric tons (10^4 kg) at 1 G (10 m/s^2) with 10 kw (10^4J/s) will work as long as it is moving 0.1 m/s or less

The problem with that is: "Moving" is relative. In deep space, any mass "moves" at any arbitrary vector depending on your frame of reference. (Discounting relativistic speeds for which time/mass dilation becomes a factor.)

Except Power(kW,HP) =/=Force(N)

I think this is the crux. There actually is no clean, simple conversion from force (=thrust) to power.

Assuming the "1dton = 10 metric tons" guideline Infojunky adopted, 1 dton requires ~100 kN of thrust for 1g of acceleration. So, 10,000 kN for a 100-dton-ship; or (obviously) 1000 "tons of thrust".

 

[infojunky]

The problem with that is: "Moving" is relative. In deep space, any mass "moves" at any arbitrary vector depending on your frame of reference. (Discounting relativistic speeds for which time/mass dilation becomes a factor.)


I think this is the crux. There actually is no clean, simple conversion from force (=thrust) to power.

Actually the issue is unit conversion. I shortcut-ed across the equations... I know bad form...