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A general advance
is the general BEM energy flux equation to show that the induced velocity can
only differ from half the velocity change in the direction of the apparent
wind.
The specific Hawt advances are: 1)Exact solution of Glauert’s
optimum rotor 2) Posing,solution and understanding of a new robust optimum
criterion 3)Drag and tip
corrections to 1)&2) 4)Proof
that normal wind regimes and windshear
favour robust blade pitch over standard min drag to lift pitch 5)Reduction of general
momentum theory to absurdium 6)More sensible simpler equations for swirl
expansion and decay 7) Prediction of hub vortex bursting 8) showing that the
ordinary BEM Hawt equations mean the dissipation of all the swirl kinetic
energy added at the rotor
And Vawt advances are 1)a Hawt-and-Betz-
consistent 2 pass BEM Model 2)its analytic solution
for tangent and passive pitch Vawts at high speed ratio 3)Proof that these
Vawts are more narrowbanded than Hawts, even without stall 4) Cam profile
for a robust cyclic pitch Vawt with the same height but broader power peak
5)Relation of isolated
blade induced drag correction to Prandtl tip correction
2) Updated Pullpump for the Flutterwell
The first Pullpump prototype on the Flutterwell was a successful testbed
for the self-snifting capability. However the original pull pump
configuration used custom seals handcrafted from plasticised PVC which were
very exposed to abrading if not jamming with dirt on a less clean well, and
could not retain the head over a calm night. The ultra-convenient foot pump
PE rising main could not be obtained at the 4" size and semi rigid 20’
lengths with connections proved no easier than PVC, though a bit cheaper.
The current second prototype incorporates the latest pull pump
configuration developed on the foot pumps with off-the-shelf seals well
protected from dirt . The dedicated static seal has to be spring-loaded to
maintain its static conformability despite potential contact every time the
pendulum passes through center . Ordinary leather foot valves do not
statically seal completely after all the hammering of pumping, and this
leakback of head can represent a major inefficiency for windpumps with the
intermittency of the wind. In all pull pumps, the ultimate hardstop will be
the bottom of the plunger against the bottom cylinder bush.
Again to protect the static leather seal, the inner cylinder pipe has
been changed from copper to PVC and for straightness and flow efficiency
sdr 21 will be tried first. Raingun 4" PE tubes are very thick wall to
take the high spraying pressures and to avoid buckling in the powered tight
winding. The biggest size of continous thin wall PE available is 3"
which is smaller than desirable. To get a 3" cylinder one could insert
3" thin wall copper DWV which is expensive and easily dented, or glue
an exterior 3.5' metal bushing (eg. 3.5" copper DWV) to a 3" PVC
cylinder. The bushing must be long for the PE glues and to bridge an
internal gap where the shuttle seal/valve clears enough to drain the water
column. Another bushing and gap may be needed above the highest static
water level to drain any renewed water column as the shuttle is raised
This system should allow one person to put the entire
pump into a high yield 4" deep well even through the Flutterwell’s yaw
bearing though the base will be redesigned to avoid this..
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