So mass is directly related to your glide time (and force/torque necessary for a pulse). I've got the glide modeled for flat terrain (a slope is easy to add in) - and I've been thinking of ways I can model the pulse such that I can verify with data.

But given that ideally we're running to optimize BSFC - the power generated shouldn't vary too much as the goal is to run only at optimum BSFC engine power. So, for a moment, consider power output constant.

Given a constant power output - the only variable inputs for one solution of the model should be mass and start/end velocity.

So, the difference between 2000kg and 1000kg gliding from 50mph to 40mph. The 2000kg body will glide for just shy of 40 seconds while the 1000kg body glides for 20 seconds. Which makes sense, if you double the mass, you double the momentum which means it should take total resistive forces almost twice as long to act on the body as those forces. I did include RR, but the difference is very low (10.6N v 21.2N).

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Mythbusters did a bit on a Helium filled football - does it get more hang time/distance. The answer is no, as helium has less mass making aero forces much more significant.

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Okay, so double the mass will nearly double the glide time - but also doubles the time necessary to accelerate. The thinking here is, stable acceleration through the pulse will yield better FE.....

Hrmmm, I may have just thought myself out of the idea.... Or just thought my way out of the method that the idea needs to be examined

I'm just going to derive some system equations on paper (what I should have done from the start) and see where that takes me - I'll probably just find that mass cancels out completely for an ideal scenario