4 ms·
> "collected wind is channeled to pick up speed" doesn't > seem to be explained anywhere -- how exactly is that > done, and how much speed would the win
by LukeShu 13y ago
> "collected wind is channeled to pick up speed" doesn't
> seem to be explained anywhere -- how exactly is that
> done, and how much speed would the wind gain?
I'm not saying that your bullshit detector isn't justified, but that is a fairly self-explanatory claim (well, the "how" part anyway, numbers are lacking).
When you have an input flow, and the cross-sectional area is decreased, the speed has to pick up to compensate.
For example, if you have a fluid flowing through a 2ft-radius tube at 10 cubic feet/second, just divide the volumetric flow rate by the area to get a velocity of 5/(2π) ft/s. If later in the tube, the radius decreases to 1ft, that reduces the cross-sectional area by a factor of 4. But, 10 ft³/s is still being pushed in, so that's what needs to come out. That comes out to 10/π ft/s.
I'm sure there are losses when the fluid is compressible, but wasn't a sentence that tipped off my BS detector.
- coldarchon 13y agoMy bullshit detector went off because they did not mention Bernoulli. http://en.wikipedia.org/wiki/Bernoulli's_principle http://en.wikipedia.org/wiki/Bernoulli's_principle
- rory096 13y agoColdarchon: Your posts are coming up dead- looks like you've been hellbanned since this post 773 days ago: https://news.ycombinator.com/item?id=3145705 https://news.ycombinator.com/item?id=3145705
- tbirdz 13y agoWow that's kind of sad. This guy has been continually commenting for over 2 years with no idea that he's been hellbanned?
- asd 13y agoI have show dead comments on and viewed his history. It's so sad - he comments every few days and oftentimes multiple times per day. He was never given chance to redeem himself to the community. That stinks.
- aaronblohowiak 13y agoNice explanation! An example comes to mind is sticking your thumb over the end of a hose.
- weland 13y agoAh, correct. As I mentioned, I'm only acquainted with fluid mechanics from a course I took a long time ago in uni. To be fair, this is basic physics though, I'll go cry myself to sleep.