Grünhaus Project, Liverpool
Director:- Prof LJS Lesley, 31 Moss Lane, Liverpool, L9 8AJ
ljslesley@aol.com
www.trampower.co.ukSecretary:- A F Stobart, BSc (Chem Eng), A Ferrand Stobart & Associates,
Bower Orchard, Church Lane, Orleton, Nr. Ludlow, SY8 4HU tel +44(0)1 568 780837
ferrand@care4free.net
www.grunweb.org.ukPatron:- The Earl of Liverpool
Dear Sirs.
The Trimblemill rating 5 kW at 10 m/sec wind speed.- see this site:
http://www.earthtoys.com/emagazine.php?issue_number=07.04.01&article=contra
is designed for 100 mph. The "tower" is made from ductile iron waterpipe, rust proof, and the central "column" can be released to lower the "head" to ground level. Mechanical drawing attached. One Trimblemill has been operating in N.Scotland for the past 17 years or so, where there are frequent gales. The "sailwing" blades may sometimes "shed canvas" but this is easily and cheaply replaced. The blade spacing between front and back was probably not right as on model tests the energy collected by each set of blades was additive, this did not happen on the Trimblemill, but we got a Cp at control box output terminals of 0.38
The control system was essentially an electronic "brake". As the application was heating [hot water or solid heat store]as the wind speed increased, and thus the turbine rotation speed, voltage etc, the control box brought more resistances into circuit to absorb the increased power available. The system was so sensitive that on one test the power delivered rose from 1 kW up to 10 kW and back to 1 kW in 60 seconds. Due to gusty conditions.
See also
www.osti.gov/energycitations/product.biblio.jsp?osti_id=5279087
www.osti.gov/energycitations/product.biblio.jsp?osti_id=7300750
which were the basis for the Trimblemill "blade" design, subsequent rotor engineering shown here:
http://www.wipo.int/pctdb/en/wo.jsp?wo=1992012343&IA=WO1992012343&DISPLAY=DESC
being re-engineered at present. To make use of a possibly better type of Axial Flux alternator, made of two sets of coils with a central magnet disk between them. Easier to engineer for accurate air gaps. Rough sketch available for this, may be patentable.
The first Trimble test unit was on a guyed tower, but this frightened the life out of the test crew in 1977 on a windy hillside in N.Yorkshire so the iron design was adopted instead.
For more information put Aerodynamic Design of a Small Contra-Rotating HAWT into Google Several good papers, patents etc come up.
And your point is?
I just don't see what you are getting at? I will let this stay up awhile so you can clarify what your purpose in this post is. If you fail to do that, it goes bye bye as gibberish. Looks like more VAWT hype to me.
