My question is fairly simple: how does one decide on the ideal dimensions and ratios for a flying wing given the target cruising speed and payload or other relevant flight characteristics.

For a more conventional aircraft, I feel like I have a fairly good intuition as far as choosing the wing design to get the desired characteristics. Wing area is roughly proportional to payload for a given flight speed. An undercambered airfoil will be slower and lift more, but not perform well inverted. A more symmetric airfoil will be faster and more acrobatic. A relatively thin airfoil will be faster, but may have a high stall speed. A higher aspect ratio wing will be more efficient. etc.

Those are not ultimatum, but rather rules of thumb and variables I consider when I am designing a new aircraft.

In the case of flying wings, I feel like I have much less intuition about how my design choices will affect the final aircraft. Specifically, what are the (general) effects of increase sweep, more taper, a larger center section, and higher aspect ratio on flying wing flight characteristics?

The designs of many of the most popular flying wings follow a relatively similar ratio: the versa is pretty similar to the Ritewing Zephyr II is pretty similar to the TBS Caphirana.


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Is this some optimal shape? If so, how come the Ritewing Zephyr III and Ritewing Drak, which are entirely different, perform so spectacularly?

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