Dear Darren Thanks very much for your excellent report. It shows the strengths and weaknesses of the Boundary Layer Turbine concept very well.
Best wishes, Kevin ----- Original Message ----- From: Schmidt, Darren To: Discussion of biomass pyrolysis and gasification Sent: Monday, October 04, 2010 11:20 AM Subject: [Gasification] Tesla Turbine Want to know the actual expected performance of boundary layer turbines. See link - dynamometer testing. http://eisg.sdsu.edu/Far/00-06%20FAR%20Appendix%20A.pdf Darren D. Schmidt, P.E., Senior Research Advisor Energy & Environmental Research Center University of North Dakota 15 North 23rd Street, Stop 9018 Grand Forks, ND 58202-9018 Phone: (701) 777-5120 Fax: (701) 777-5181 [email protected] www.undeerc.org From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Sunday, October 03, 2010 5:59 AM To: [email protected] Subject: Re: [Gasification] tests to design a new cheap gasifier fan Jim, Stay away from Tesla turbines. I've already played with them and they are a pain. I ended up laser cutting my disks then using #4 flat washers as spacers to get the roughly .015 spacing between plates. The problem was dealing with the lack of flatness in the sheet stock. Granted I was using it as a power turbine, but it was still painful. Given how close the disks need to be I wouldn't go there. Any little bit of tars or ash and they will plug. I would stay on your present course. Stephen -----Original Message----- From: jim mason <[email protected]> To: Discussion of biomass pyrolysis and gasification <[email protected]> Sent: Sun, Oct 3, 2010 6:33 am Subject: Re: [Gasification] tests to design a new cheap gasifier fan the rotor made from the spinning disk with vanes between we have notyet tested. we should i agree. we have testing the one sided versionwith vanes at various angles forward and back from perpendicular. iwas surprised to find it makes little difference. backward rake,espeically curve backwards at the tip is done with pro fans to reducenoise, not increase pressure/vac. it actually reduces performance abit. it has taken awhile to get through my head that these fans are workingas centrifugal devices, not pressure devices. the blades are notlevers or pumps. they are simple accelerators for air mass. yourpressure/vac is coming from velocity and inertia/momentum. this is why the tightness to the walls makes little difference. i'vemoved the rotor / wall tolerance around quite a bit and saw verylittle diffference. i've read this is also why you see less doublewalled rotors that one might expect. but i've yet to test this socan't really say. greg says he gets 25% more out of these types. some devices in the weed blower vac world put vanes on both sides ofteh disk. but i think this is to prevent the weeds from getting stuckon the back of the disk. see the toro blower for example of this. arnt raises an interesting concern about the rotor bending. the otherway to deal with this would be to make a full slot for the vanes, andpush the vanes through so they stick out on both sides. put a hole inthe center so air can feed to both sides of the rotor. and . . . i have to suggest it. . . this might finally be a reasonable application for a tesla turbine.many parallel disks, no vanes or welding. problem is the distancebetween the disks needs to be related to the laminar layer thicknessat the rpms one is running. the distances are usually very small.like a few 100ths of an inch. these are difficult tolerances tomaintain with junk cut metal. however, it begs to be tried. we will soon here. maybe at theworkshop next weekend. j On Sat, Oct 2, 2010 at 7:39 PM, Greg Manning <[email protected]> wrote:> > > Greetings Jim, and list members.> > Jim, if you want a better fan, (and cheaper), simply make 2 disks (one> mounts on the shaft, the other has the larger hole for the inlet.)> > then use strips of heavy tin (or light gauge metal) and form them into a Z> shape (well, an L with a dog leg the other end, and the opposite way,> somewhat like a "90 degree Z")> > take these and pop rivet with STEEL rivets (NOT aluminum ones) so they are> sandwiched between the two disks in a radial fashion (like your welded> version on your site, BUT with the extra disk on the inlet side of things.> > the extra disk should run as close as it can to the outer housing the> Bernoulli principal will help stabilize the outer disk, and the outer disk> will add about 25% more suction to the unit for the same RPM (therefore the> entire unit could be built smaller and lighter).> > Greg Manning,> Canadian Gasifier Ltd.> Building Hi-Performance Gasifiers, Since 2001> > Brandon, Manitoba, Canada> 1 (204) 726-1851> > > > -----Original Message-----> From: [email protected]> [mailto:[email protected]]on Behalf Of jim> mason> Sent: Saturday, October 02, 2010 4:58 PM> To: [email protected]> Subject: [Gasification] tests to design a new cheap gasifier fan> > > we've been doing some work lately to design a new fan/blower that will> produce the needed vac and heat tolerance for gasifier operation. as> we all know, there is not an inexpensive source for such a thing from> other industries and applications. thus we had to build one for the> early gek kits.> > the original gek fan proved to not be strong enough once we finally> characterized the vac numbers that produce the flow/heat rates that> correspond to full tar conversion. the ejector/venturi solution we're> using currently produces plenty of vac and is very flexible, but> requires compressed air. this is not good for many off grid> situations. thus we still need a good fan/blower source. and one> that works on 12vdc, not an ac source.> > here's the info an pictures of our recent tests to produce this. we> are working towards a much simplified solution that also gets rid of> the welding to make it. this is based on the common car/truck fasco> type fan motor.> > http://gekgasifier.com/forums/showthread.php?t=455> > jim> > > > --> ----------------------------------------------------------------------------> --> Jim Mason> Website: http://www.whatiamupto.com> Current Projects:> - Gasifier Experimenters Kit (the GEK): http://www.gekgasifier.com> - Escape from Berkeley alt fuels vehicle race: www.escapefromberkeley.com> - ALL Power Labs on Twitter: http://twitter.com/allpowerlabs> - Shipyard Announce list:> http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com> > _______________________________________________> Gasification mailing list> [email protected]> http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenerg> ylists.org> No virus found in this incoming message.> Checked by AVG - www.avg.com> Version: 9.0.856 / Virus Database: 271.1.1/3158 - Release Date: 10/02/10> 01:34:00> > > _______________________________________________> Gasification mailing list> [email protected]> http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org> -- ------------------------------------------------------------------------------Jim MasonWebsite: http://www.whatiamupto.comCurrent Projects: - Gasifier Experimenters Kit (the GEK): http://www.gekgasifier.com - Escape from Berkeley alt fuels vehicle race: www.escapefromberkeley.com - ALL Power Labs on Twitter: http://twitter.com/allpowerlabs - Shipyard Announce list:http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com _______________________________________________Gasification mailing [email protected]http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org ------------------------------------------------------------------------------ _______________________________________________ Gasification mailing list [email protected] http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org ------------------------------------------------------------------------------ No virus found in this message. 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