Consider this question and comment I added to the wiki page on added-mass.
How does one determine how much of the surrounding mass to add? It sounds like added-mass is an egineering fudge factor rather than good science. http://en.wikipedia.org/wiki/Added_mass Harry Rick Monteverde wrote: > Use your hand to push a handful of air. Now imagine you have a vortex > and push that with your hand. You're moving more air, more reaction > mass. Isn't that what they mean in the article, or they just don't say > at all? The vortex ties air together into a momentary 'thing' that has > more mass than the smaller handful of air. I doubt the increase in > reaction mass at insect reynolds numbers does much, but I guess it all > adds up with rapid wing-beats. The viscous drag against the larger pulse > of air moving through the surrounding air is a good thing too if you're > pushing either down or backwards or both to get thrust and lift. > Probably would work even better on a larger scale - like for human > powered flight. Flonk... Flonk... flonk... > > -----Original Message----- > From: Harry Veeder [mailto:[EMAIL PROTECTED] > Sent: Wednesday, November 30, 2005 1:52 PM > To: [email protected] > Subject: Re: Secrets of bee flight revealed > > > The article mentions the forces provided by the vortices...but the > origin of the "added-mass force" is not explained. > > quote: >> Lastly, there is another peculiar force known as >> added-mass force which peaks at the ends of each stroke and is related > >> to acceleration as the wings direction changes. > > > Harry > > Rick Monteverde wrote: > >> Conceptually that means more stuff to push off of. <???> >> >> These kinds of wings create vortices of air which feature increased >> mass and resistance to downward/rearward movement than a similar >> surface would encounter while slicing through the medium in a more >> laminar mode. Probably get increased stability too. >> > > > > >
