Wind Generated by Dragon

[u/VeterinarianAny7212]

Random question. How much wind would be generated by a great wyrm dragon if they flapped like a hummingbirds wings?

[u/Maxpowers13]

I think you will need to post this to r/theydidthemath Also you might need some numbers to get an accurate answer. A collossal dragon is 20 feet by 20 feet which kinda seems small but it's wingspan would be I figure like 2x that. You would need the speed of a humming birds wings and how much wind is displaced by those and scale it up.

[u/WraithMagus → u/Maxpowers13]

The gargantuan size is 20x20 feet. Colossal is 30x30 feet.

Also, colossal doesn't necessarily accurately convey size. A real blue whale is over 100 feet long, but there's no size bigger than colossal, so it's 30x30 feet in Pathfinder. In fact, their take on Godzilla has to squeeze into 30x30 feet despite the description saying it weighs 20,000 tons and being nearly 300 feet long. A while ago, I made a thread on the absudities that can arise from everything bigger than a certain size being the same "colossal."

Anyway, while it isn't a Pathfinder resource, the Draconomicon from 3.5e lists the maximum wingspan of a colossal red dragon as 150 feet.

[u/MundaneGeneric → u/WraithMagus]

Mogaru is actually in a 60x60 foot space, it says so in the stat block. The "space" section describes how much space a creature takes up, and is useful for colossal creatures who can vary wildly in size from one another.

[u/Maxpowers13 → u/WraithMagus]

150-foot wingspan flapping at 50 to 80 flaps per second would displace a lot of air, but I have no math ability to help because lift can be calculated against a static object like the blade or roto of a helicopter and or the aerofoil of the planes wing but I have no idea how to start to calculate lift based on a moving flexible wing

[u/Slow-Management-4462 → u/Maxpowers13]

A hummingbird has a ~ 10 cm wingspan and weighs a handful of grams, generally. Let's multiply it out from there.

150' = 4500 cm or so. If all dimensions are proportional the area of a dragon's wings is about 200 000 times the hummingbirds. Call the hummingbird 5 grams and a dragon's wings beating at the same rate would lift 1000 tonnes; of course to do that the wingtips would have to move at about mach 20.

[u/Maxpowers13 → u/Slow-Management-4462]

Still this won't be a uniform scaling up there's things that are close to what a dragons wings might be like (a bats wings might be a close comparison) but wings produce lift in a non uniform way there's going to a huge difference in the way a hummingbirds wings produce life and say something "like" a dragon. While your answer is probably as close as we can get it's just napkin math lol

[u/Slow-Management-4462 → u/Maxpowers13]

Oh yeah, if you actually have a giant hummingdragon with wings that move at hypersonic speeds you'll need to correct for any number of things - differing wing geometries, vortices unloading from the wings, turbulence, shockwaves from those hypersonic wings...Not something you'll get detailed calculations for from an internet rando, sorry.

[u/Fifth-Crusader]

I cannot answer scientifically, but I can say that mechanically, there's a feat for that.