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Posted by: Iranon
« on: April 24, 2018, 10:48:57 PM »

Tonnage efficiency. Assuming a fixed engine size and a given weight budget for engines+fuel, that will net you the longest range at a given speed or vice versa.

Byron solved this in 2012. Here's my most complete look at it: http://aurora2.pentarch.org/index.php?topic=9146.0
Posted by: Jovus
« on: April 24, 2018, 03:20:21 PM »

Quote from: Iranon on September 17, 2016, 05:16:43 PM
With freely scaleable missile engines, your most efficient propulsion setup uses 31% of engine weight for fuel.
With a fixed engine size (ship or missile), your most efficient propulsion setup uses 40% of engine weight for fuel.
Short-ranged high-performance missiles will often use less fuel, because the sweet ratio with your highest power multiplier results in excessive range and you're rather have more speed.

What math is this based on? What is optimized by this 'efficiency' and what formula are you using? I've been noodling around with engine formulae and haven't found anything like this, but to be fair I've also not tried really hard or sat down with pen and paper to do a real analysis - I've just been throwing crap at my Python IDLE to see what sticks.

(Not trying to call you out specific-like, Iranon; you're just the person I found saying this via the forum search.)