Stephen, This technology is already used for towing hydrophone streamers in geophys, but it doesn't work quite like you suggest. There's no need for two boats, and instead there's a paid of towed hydrofoils behind one boat, with the support line tensioned between them. The low mass of the hydrofoils means that there's no real shock on the cable in rough seas. The bubble generators would be strung out on streamers behind this towed line.
The bubbles would be distributed by a number of 'birds' which are depth-set from the control room - just like the hydrophones are currently. To get good saturation with bubbles, I suggest that they'd need to be delivered at a variety of depths - but whether that's worth doing depends of course on the lifetime. No use dropping them ten metres down if they don't last long enough to mix or rise. A On 27 April 2011 13:05, Stephen Salter <[email protected]> wrote: > Hi All > > Michael Hayes asks about how bubbles could be deployed. > > One possibility would be for a pair of wind-driven vessels to sail side by > side at, say, a kilometre separation, attached to each other by a buoyant, > streamlined tether. > > The chord of the tether would be about 100 mm. In plan it would form a > catenary with a generous bulge to reduce the tensile load. The nose of > tether would contain a strong Kevlar or carbon tension member. Behind this > would be a number of high-pressure air-lines taking very well filtered air > from each vessel to a porous strip near the nose of the foil section and > running the full length. The drag of the tether would be reduced by the > bubble layer on the underside. > > The tether would have to be elastic enough to follow the curvature of the > wave slope. In most sea states this is surprisingly low but elasticity can > be increased by running the tensile member in a series of S shapes. > > The vessels need power but could generate this in the same way as suggested > for the cloud albedo project. Indeed it would not be difficult to design a > dual purpose vessel which would change mode according to cloud conditions. > It would be convenient if the vessels were symmetrical fore and aft so that > they could tack by going into reverse. > > The design does need information on bubble life and the best bubble > diameter and I would be most grateful for any advice on this matter. > > Michael mentions the Dracone project. I worked on this in a very junior > capacity in 1960 but a kilometre wide bubble wake would be cheaper if the > bubbles can last long enough and less of a risk than a Dracone that got > loose. > > Stephen > > Emeritus Professor of Engineering Design > Institute for Energy Systems > School of Engineering > Mayfield Road > University of Edinburgh EH9 3JL > Scotland > Tel +44 131 650 5704 > Mobile 07795 203 195 > www.see.ed.ac.uk/~shs > > > > On 26/04/2011 23:21, Michael Hayes wrote: > >> Please help me understand the mechanics of Bright Water deployment. I have >> spent many months living on the Bering Sea (in winter) and have piloted >> 150ft fishing vessels in that area for countless hours. I have watched the >> sea continually produce white caps for as far as I could see for days and >> weeks at a time. How can a practical, cost effective and meaningful use of >> bright water be deployed which comes even close to .0001 percent of the >> natural production of white caps? The energy and equipment needed to cover >> any meaningful amount of the sea is difficult for me to comprehend. >> Outfitting fishing fleets with the needed equipment and paying the boat >> owners to run the gear is possible. But, we are only talking about a bright >> water wake which lasts for only a short distance...at best. >> >> Designing autonomous platforms specifically for the mission may be >> possible, but, one storm could beach every single platform within a few >> hours. Who and how will they be collected and sent back out? This, from a >> seaman's point of view, is difficult to see as being practical. I have >> studied the concept though what has been offered here and through other >> links. The mechanical challenge of producing such small bubbles is >> interesting and I have even spent time thinking through the possible use >> high throughput ultrasonic injectors. But, I still come back to the >> questions of; 1) how can bright water be practically deployed? 2) How can >> the investment be justified when the wide area effect is so tenuous? 3) >> Would not reflective large surface rafts provide a more cost effective long >> term overall result? >> >> There is the option of a reflective form of the Dracone Barge as a useful >> way to deploy large area ocean surface SRM. " >> http://en.wikipedia.org/wiki/Dracone_barge. >> >> If such barges were deployed in large numbers a large area rafting system >> could be secured in needed areas and moved as the season changes. With small >> desalinization pods attached, we could have not just have low cost/long >> term/flexible ocean surface SRM but a nice supply of needed fresh water. >> Sell the fresh water and buy more bags!!!! >> >> I ask your help in understanding how bright water can be a competitive >> form of SRM. >> -- >> You received this message because you are subscribed to the Google Groups >> "geoengineering" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/geoengineering?hl=en. >> > > -- > The University of Edinburgh is a charitable body, registered in > Scotland, with registration number SC005336. > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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