Ahhh the vortices! Only relatively recently were these observed in experiments done on 'bumble bee' flight. IIRC, they were shown to be a significant source of lift for these large bees, without which they either could not fly or certainly not fly as well as they do!
Charlie Nelson Water Phantom C&C 36 XL/kcb Sent from my iPhone > On Jul 25, 2016, at 8:08 PM, Don Wagner via CnC-List <cnc-list@cnc-list.com> > wrote: > > This is technically known as "vortex shedding". It's a natural phenomena > caused by the air flow around a round cylinder ( the rod or the wire) and > occurs at certain wind speeds. At normal speeds, normal flow occurs, and > there's no vibration. At certain higher speeds, vortexes develop, and induce > vibrations in the rigging. Tightening or loosing the rigging will usually > reduce the effect. You can find a more complete description on the internet. > > Note: Commercial airliners have observed the problem at their wing tips, and > many recently added small winglets at the ends of their wings. I believe > this reduces energy loss, reduces the vibration, and improves their fuel > mileage. > > Don Wagner > C&C 41 CB > Der Baron > West River MD > > > > -----Original Message----- From: Christian Tirtirau via CnC-List > Sent: Monday, July 25, 2016 11:04 AM > To: cnc-list@cnc-list.com > Cc: Christian Tirtirau > Subject: Stus-List Singing Rigging > > Hello fellow seers, > I'm getting this humming in the mast as soon as I have a little breeze while > on the mooring ball and it's really annoying. At first I thought it was a > generator or an engine sound propagated by water but I realized it's the > strings of this big violin that are singing. Any idea how you get rid of that > without messing up the rig balance? Is it the baby stay? I have a lower that > is a little loose and when I tension it the sound pitch changes but does not > go away. > Cheers, > Christian Tirtirau > C&C 37 Northern Light > > _______________________________________________ > > This list is supported by the generous donations of our members. If you like > what we do, please help us pay for our costs by donating. All Contributions > are greatly appreciated! > > _______________________________________________ > > This list is supported by the generous donations of our members. If you like > what we do, please help us pay for our costs by donating. All Contributions > are greatly appreciated! _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
