PROUDLY DESIGNED AND ENGINEERED IN THE USA!

As featured at the 2017 Small Wind Conference

Heat & Power 24/7

from Wind Power

A PRACTICAL REALITY

overview

  • 12-bladed, upwind, direct-drive, non-furling HAWT
  • Natural Sunflower look
  • Ground level servicing, no climbing
  • Short towers work for us
  • CPOWER is ~ 10 x's  SoA
  • 24/7 Non Electrical Flameless Heat & Power on site off grid
  • Disturbingly Cost effective
  • Neighbor friendly, virtually noiseless with zero flicker
  • Slow speed safety rotor
  • A reaction turbine operating below its critical Reynold’s Number
  • It used passing thru its Critical Reynold’s Number to reliably and repeatedly pivot out of the wind for decades
  • But, this prevented it from ever reaching higher power levels

The Machine That Won The West

 

  • Harvests only 5-6% of the lift forces developed, at best
  • Directly interacts with only a tiny percentage of the molecules crossing its rotor disc
  • The Bernoulli energy equation boldly predicts, but fails to provide a valid Blade torque-producing mechanism.
    It is clearly wrong!
  • Operates at TSR of 6 or more
  • Tall towers Required to reach non-turbulent airs

TODAY'S STATE-OF-THE-ART MACHINE (SoA)

 

Is this the Ultimate Wind Machine?

  • Most of the Lift & Reaction Forces drive the generator vs tip over the tower.
  • All of the molecules passing through the rotor’s plane interact with the rotor.
  • The blade torque mechanism is clear.
  • Short towers work for us.  Ground level servicing
  • Operates at TSR's of 3 or less

My Resultant Machine…

takes the opposite design approach to the current state of the art.

It's not over until the fat lady sings.

REAPER MODELS IN TESTING

(AVAILABLE SOON)

Wind and Water US Patent # 7,989,973  +  9,816,383  +  9,816,384 + pending

General Lift/Drag aero Model

  • Blade torque goes to ZERO at TSR = L/D
  • Tower forces are 10 TIMES the generator forces when TSRs are greater than 6 and rising
  • CPOWER is ~ 10 x's  SoA

why?

I am aware that many of you out there are certain that since the best utility scale machines are approaching GOD's, aka Betz's Limit, that there is no point in wasting your time looking further. It reminds me of the comfy smug physicists at the turn of the 19th century who thought that all there was to physics was just a little more precision in their experiments & all would be explained.

Now as then, there are a few niggling nagging details & questions I have for you:

  1. The chord of the blade at the rotor's OD on conventional 3-bladed machines is almost always in the plane of the rotor because of the preferred TSR of 6 or more. This means that only 5-6% of the Lift Forces developed, at best, can be harvested as energies by the generator; the balance are uselessly and counter productively trying to tip over the tower, requiring stronger and more expensive towers, foundations, shaft bearing, etc. The additional operational requirement of tall towers only exasperates this situation.
  2. Additionally, looking at photographs and doing a few simple calculations, it is clear that very few of the molecules traversing the rotor's disc actually interact directly with the few blades. How can this be an efficient harvesting of the resource?
  3. Additionally unrelatedly, the Bernoulli Equation states that the wind's velocity must slow down as it passes through the rotor disc. So I ask, OK, explain to me the mechanism of how this slowing down puts torque on my blades, so that I the designer can rationally design the blades? No mechanism exists: e.g. the Bernoulli Energy Equation cannot be correct.

Based on these simple observations, as a long term machine designer, I long thought that there must exist a better solution making more effective use of materials and the wind resource to be exploited. It's solution was not obvious, as dozens, if not hundreds of companies, have shown us plenty of bad ones.  To me, this unusual proliferation of bad ideas is a symptom that the underlying theory is not clear, not correct.

Believing that most refinements to the existing 3-bladed approach had likely been already discovered, I took the opposite design approach looking for solutions where most of the forces developed would be driving the generator vs tipping over the tower. After a decade or so of work, what follows is my result.

There exist three different “Force Velocities”

  • Drag
  • Reaction
  • Lift

Reaper uses only Reaction and Lift Forces

what?

My resultant wind machine system most resembles the 19th century American farm wind mill, but I fixed its previous limitations for generating power. Now it has 12 thick, 25% chord, large nose radiused, OJB designed high lift, light weight, high tech aero blades which constructively and instantly interact to uniquely guide the flow through its array, combined with a unique, simple and critically necessary speed control system that allows it to linearly track the wind, keeping a constant wind angle of attack on the blades, aka TSR, over the full range of wind speeds. While it is quite capable of merely pumping water, we/I have equipped it to do far more, so that it can provide both heat and power, CHP, 24/7 for all your possible uses. Let's leave our petro resources in the ground for future generations.

Wind is required, but tall towers not.

Conventional high speed 3-bladed machines running at TSR's of 6 or more, require tall towers and non turbulent air flows as any turbulence confronting their naked narrow chorded blades instantly puts the blade into stall conditions; e.g. the flow to separate from the low pressure side of the blades; constant speed high inertia rotors only add to the problem by not allowing the rotor to adjust to different wind speeds. But, my variable speed reaction turbine operating at TSR's of 3 or less with its overlapping constructively interacting blades interact to uniquely enhance the Lift Forces keeping the flow attached under nearly all conditions. Make no mistake, we are strictly talking about Lift & Reaction forces here;  no Drag Forces are involved.  Short towers and turbulent conditions work for us; who needs zoning hassles and upset neighbors when they can all be avoided by a little creative design?

Reaper’s Blade Layout Features

  • The rotor rotates the air flow, harvesting Newton’s Momentum Exchange
  • The lift forces are oriented to mainly drive the generator
  • The overlapping blades actively employ the Blown Flap Effect
  • Blade tip speeds are maximized to enhance Coandă effects

How best to harvest this wild wind beast?

Indirect WATER Heater/CHILLER

  • Dual coil for wind, solar and wood renewable energy inputs for hot water 24/7
  • Heat easily stored overnite and longer
  • Modular, expandable to suit

the devil is in the details

Additionally my machines have four more unique features that conventional machines do not share that mimic extra tower height and/or add to the energy capture:

  1. An inverted nose dish that deflects normally wasted central air flows, to speed up the average air speed through the blade array achieving much the same as a taller tower.
  2. Our Unique Hoerner's Wing Tip sculptured blades that uniquely define my rotor's OD that virtually extend the rotor's effective diameter while also decreasing the tip vortices, lowering the drag and increasing the energy harvested much like a shroud or extra tower height does, but less the cost and weight of the shroud/extra tower.
  3. The Flow is channeled and accelerated to increase the local velocity off the blade trailing edges, enhancing the flow on its low pressure side of the blade and energizing the boundary layer of its mating blades, creating what is known as a "Blown Flap Effect" enhancing the Coandă and Katzmayr Lift effects keeping the flow attached during nearly all wind speeds and conditions, turbulent or not.

Hoerner's Sculptured Wing (Blade) Tips

Wind, as we all know, is the most fickle of energy sources, its speed bouncing up and down like some erratic, neurotic yo-yo. Yet we like our electrical supply to be steady-eddy 24/7. What is a designer to do? My solution was to have the electrical part of the system max out at say 11-12 mph, near the local average wind velocity, maintaining a very desirable higher electrical "capacity factor" and have all the rest be turned into heat which can be easily stored short-term. Smaller household size systems have a small hydraulic driven DC Genset, ~ 2 KW, with chargeable batteries connected to an inverter to supply grid quality electric power 24/7 to all your non heating loads. Larger systems additionally are equipped with an AC Genset synchronous generator.

As we all know, the wind does not always blow, so the end point of my heating system is a special "indirect" water heater with dual-coil input. One coil is attached to my wind machine, the other attached to either a wood stove, solar panel or a concentrated utility gas or electric heat source. End result: seamless electrical power and hot water 24/7 for all your "on demand" or radiant heating as well as electrical power needs.

nucelle assembly

 

My system has gears, but no "gearbox," meaning no mechanical gear drive, nor its problems.

The 12 wind-driven blades directly drive a large slow-turning hydraulic gear pump, which is connected through a swivel joint/yawl bearing via hoses, internal to the tower, in a closed loop with the Ground-Level "Power Kart" with the DC and AC Gensets driven via a high speed motors, the "indirect" water heater, filter and all controls. Ordinarily hydraulic gear pumps are thought to be too inefficient for this application, but that is not the case with how I use them, as heat is the major product of my system, so all of it is saved and transported to storage and eventually used.

An hydraulic drive was chosen as it is approximately 1/10th the size, weight and complexity of the electrical drive it replaces, more so since it needs no gearbox, reducing the size and weight of the towers and foundation, plus its working fluid, unlike electrons, carries the normally lost heat down to the Power Kart where it may be harvested and stored. Since the tower top pumps are physically not much different in size and weight from 10 to 100 KW, this allows me to use the same tower for all three sizes, all of which can be readily exchanged as conditions warrant to suit the customers' needs. Additionally as I stated, this hydraulic system permits an exceptionally simple control system to track the wind, orders of magnitude simpler, more rugged, reliable and cost-effective than any competing electrical system, known to the author. A simple precision orifice in the form of a simple needle valve or replaceable set screw with a hole in it does the trick! Once it is sized for a particular model machine, it works automatically over the whole wind speed range, plus it has a dual purpose: it also turns the fluid under pressure into heat!

IT'S HYDRAULIC, LOVE

  • 1/20th the size & weight of electrics
  • Unmatched compact ruggedness
  • No gear box required
  • Unique speed control opportunities
  • Combined Heat and Power (CHP)

Power Kart

  • Modular
  • Portable
  • Flexible
  • Expandable

The pump in the Nucelle assembly at the very top of the tower has a pressure relief valve with an integral heat exchanger, which recirculates excess fluid flow whenever the unit is operating above rated wind speed while allowing continuous power production at the Power Kart, even during storms. We strive to never having to shut down the system; who wants to be without power in a storm? The Power Kart also includes a shut-off valve to stop the turbine at any time to facilitate repairs, filter changing and/or decommissioning.

EASILY SERVICEABLE, no climbing,

 ground level maintenance

One-man operation
up and down

Industrial strength behind a pretty face

Installs in tight spaces

The Betz Limit is generally met and exceeded by the Reaction Forces alone; the Lift Force Energies mostly drive the generator vs tip over the tower and are totally extra freebie bennies not accredited in the Bernoulli Energy Equation.

Basically this array is constructed like a giant bicycle wheel with a cinched heavy duty plastic shipping strap acting as the rim, crimped into a pocket in the end of the spar of each blade keeping it from moving and fatiguing; it is a reaction turbine operating above its critical Reynolds number with interacting overlapping blades employing enhanced lift force capabilities. The old farm wind mill it replaces was also a reaction turbine, but it did not have the Hi Lift Aero Blades nor a sophisticated speed control system; it operated below its critical Reynolds number in Laminar flow regimes and apparently used this feature of nature to repeatedly and reliable pivot its blade array out of the wind stream to protect itself. However, this meant that it could never operate successfully at the higher power levels, nor was it designed structurally to do so. My machine is.

The number of blades in the array is truly unique: more blades would cause it to operate below the critical Reynolds numbers, while fewer blades would be too far apart to constructively interact.

My machine thoroughly dispatches A. Betz's silly theory of limits, which is coincidental not casual, and routinely exceeds COE (conservation of energy) equation predictions, as written, by several times, which is rendered KAPUT by the mere existance of this machine.

A Reaction Turbine

with Enhanced Lift Features

 

  • Operates above its critical Reynold’s Number
  • Interacting blades keep turbulent flows attached
  • Newton’s Momentum Exchange Forces harvested
  • Lift Forces mostly oriented to drive generator vs tip over the tower
  • Blades back wind at 3 times the wind speed, preventing over speed in any condition
  • Short towers work for us
  • Effective, simple TSR speed control
  • Approx 12 Blades required

Most Importantly

  • Torque from Lift & Reaction Forces increase as D3, but the Power only increases as D2, not because the “Kinetic Energies” are being converted into “Potential Energies”, but because the power is proportional to these forces times the rotor RPM, which decreases as 1/D to keep the same TSR; hence the net power is proportional to D2.
  • A machine designer, knowing this, would design her machine similar to Reaper vs today’s three-bladed machines.
  • Proving or disproving this concept is the main goal of my first machines.
  • Designed & funded by OJ Birkestrand. ojbirkestrand@rabbittool.com (800) OJB-CORP

in summary

I guarantee that all of my machines exceed the Betz Limit, mainly because the Lift Forces are not properly accredited in the Bernoulli Energy Equation, but also because Newton's Momentum exchange forces are wrongfully excluded.

For more information, questions
or to place an order, contact us today.

We welcome your comments.

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Rabbit Tool USA Inc

Rabbit Tool U.S.A., Inc

105 - 9th Street

Rock Island, IL 61201

TEL/FAX (309) 793-4375

ojbirkestrand@rabbittool.com

© 1992 Rabbit Tool USA, Inc. Printed in USA. Patent Pending.

TEL/FAX (309) 793-4375