Recent content by normofthenort

And while we're at it, I've got another aerodynamic puzzle, also about fans: A couple of years ago, I was introduced (by a Canadian science show on TV) to a fascinating and counter-intuitive fact: If you're trying to use your breath to inflate (say) a large plastic garbage bag, it is MUCH...

Have I really stumped the assembly here?

Yes, that photo is a great example. The profile of those fan blades is JUST EXACTLY like some propellors I've seen, except that the rotational direction is exactly BACKWARDS! On the props, the curved (convex) shape is the leading edge, and the outside trailing-edge tip is "swept back", creating...

I've got one at home, but I'm not there now. Here, they've got ceiling fans that look exactly like ship propellors, but they go in only one direction, which would be reverse for a ship -- straight edge first, convex edge trailing. That's really what prompted the question. If you've got a...

No, Dave, I've never seen a propellor blade with a concave leading edge, they're all convex. But I've seen lots of FAN BLADES with concave leading edges, and some with straight ones, too. And their TRAILING edges are all convex, like the LEADING edges of the propellors. That's my point, the fact...

Here's a related question: Both (air) fan blades and ships' propellor blades often have one side that's curved (convex) and another side that's either straight or concave. But the orientation is OPPOSITE on fan blades and propellors! I.e., props seem to lead with their curved (convex) edge, as...