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Re: [AWES] Rim Driven Wind Turbine (RDWT),drag-based and lift-based blades

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  • dave santos
    Doug wrote- The rule of thumb is if your TSR is less than 1, it s a drag machine and if your TSR is more than one, it s a lift machine. This is a misleading
    Message 1 of 26 , Oct 12, 2012
      Doug wrote- "The rule of thumb is if your TSR is less than 1, it's a drag machine and if your TSR is more than one, it's a lift machine. "

      This is a misleading folk notion of aerodynamics, of how Lift and Drag really are defined-

      Wikipedia-

      Lift is the component of aerodynamic force that is perpendicular to the oncoming flow direction.[1] It contrasts with the drag force, which is the component of the surface force parallel to the flow direction.

      http://en.wikipedia.org/wiki/Lift_(force)


      HAWT and Darrieus are lift-based*. Savonious is drag-based.

      * "-based" defined as the principle-of-operation


    • Doug
      Dave S. Why make yourself look endlessly silly? Consumer Reports:
      Message 2 of 26 , Oct 13, 2012
        Dave S. Why make yourself look endlessly silly? Consumer Reports:

        http://news.consumerreports.org/home/2012/08/results-of-consumer-reports-wind-turbine-tests.html

        Why does the Honeywell turbines not still use cloth blades on bicycle spokes? Why did they ever? How much does it cost? What about the excess weight? Does it really put out 1500 Watts?

        You don't know the answer to any of those questions, just like you don't know antything about wind energy, period.

        Honeywell STARTS with LIES:
        1) They compare their turbine to "turbines with a gearbox". Only the uninformed imagine there is a competing 6-foot diameter turbine with a gearbox - there are NONE.
        2) They claim to start producing electricity in a 2 mph wind or whatever - I watch turbines and anemometers for hours every day - the wind can't even power up an inverter til you have 5 or 6 mph, even if your turbine was 100% efficient!.

        Dave S., I took 2 seconds to google "cost of a honeywell wind turbine" and the first article I clicked on was Consumer Reports".
        Consumer Reports found the turbine put out 4 kWH in 15 Months versus about 1500 kWh promised for the site. That is ONE QUARTER OF ONE PERCENT of the claimed results from this turbine. You might as well admit it produces essentially NOTHING. I think most experts just say whatever it takes to get rid of you quickly - "sure it works great"...

        Consumer Reports states that their Honeywell turbine would take SEVERAL MILLENIA to pay for itself, yet it has a predicted 20-year lifetime. I can show you a decent competing turbine for about $500 versus $11,000 for this hunk-o-junk.

        http://news.consumerreports.org/home/2012/08/results-of-consumer-reports-wind-turbine-tests.html

        Here's a cut-and-paste for those online without internet access (huh?)
        Energy
        Recouping cost of wind turbine may take more than a lifetime
        Aug 6, 2012 12:00 PM

        Wind power has been the fastest growing source of new electric power, according to the U.S. Energy Information Administration. But if you're considering a wind turbine to supplement your home's power, consider our experience with one product, the Honeywell WT6500 Wind Turbine, a cautionary tale.

        Among the few wind turbines that can be mounted on a roof, the WT6500 is similar to traditional wind turbines: Any unused energy it generates can be sent or sold to a utility for credit off your power bill. But it's quieter than traditional turbines, and according to the manufacturer WindTronics, starts generating power at lower wind speeds. The company claims the unit starts spinning from winds of a mere 0.5 mphâ€"with electricity generated from only 3 mph. Traditional gearbox wind turbines, said the company, require at least 7.5-mph winds to start generating power.

        A tool on Windtronics' website had calculated we'd get 1,155 kWh per year at the 12-mph average it predicted for our area of Yonkers, New York. And the authorized installer, during his initial visit, didn't say the roof of our headquarters might generate any less, but that rating is at a height of 164 feet, not the 33 feet WindTronics requires for rooftop installations.

        In the 15 months since the turbine was installed, though, it has delivered less than 4 kWhâ€"enough only to power a 12,000 btu window air conditioner for one afternoon. A company representative in charge of installations worldwide recently visited our offices and confirmed that our test model was correctly installed. What's more, he told us that while the WT6500 should start generating power at about 3 mph, the initial juice goes just to power the system's inverter, which must be running before it supplies any AC power elsewhere. The true wind speed needed to start producing AC while the inverter is on is 6 mph, not far from the 7.5 mph needed by a traditional gearbox wind turbine.

        The Honeywell costs $11,000 installed, comes with a five-year warranty and has a 20-year expected product life. But having a thorough site analysis by a manufacturer-authorized installer, backed by your own research on websites such as the National Renewable Energy Laboratory, is vital.

        At the rate the WT6500 is delivering power at our test site, it would take several millennia for the product to pay for itself in savingsâ€"not the 56 years it would take even with the 1,155 kWh quote we received.

        â€"Ed Perratore


        --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
        >
        > Doug,
        >
        > The electrical upgrade was not the Honeywell product, but the farm grid side.
        >
        > You also managed to comepletly tune-out Coy's expert opinion in your hope of knocking the Honeywell. Coy clearly has far more experience with turbines that you do (and he is more optimistic about AWE). He has installed and maintained everything from big GEs to an old "Dutch" poldermill.
        >
        > Don't forget your diode blew on Gipe, as if this sort of part failure is really how to judge a bad turbine,
        >
        > daveS
        >
      • Doug
        Dave: I GAVE YOU the RULE OF THUMB. PERIOD. You are an uninformed NEWBIE who knows nothing, PERIOD.
        Message 3 of 26 , Oct 13, 2012
          Dave:
          I GAVE YOU the RULE OF THUMB. PERIOD. You are an uninformed NEWBIE who knows nothing, PERIOD.

          --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
          >
          > Doug wrote- "The rule of thumb is if your TSR is less than 1, it's a drag machine and if your TSR is more than one, it's a lift machine. "
          >
          > This is a misleading folk notion of aerodynamics, of how Lift and Drag really are defined-
          >
          > Wikipedia-
          >
          > Lift�is the�component of aerodynamic force that is�perpendicular�to the�oncoming�flow direction.[1]�It contrasts with the�drag�force, which is the component of the surface force�parallel�to the flow direction.
          >
          > http://en.wikipedia.org/wiki/Lift_(force)
          >
          >
          >
          > HAWT and Darrieus are lift-based*. Savonious is drag-based.
          >
          >
          > * "-based" defined as the principle-of-operation
          >
        • dave santos
          Doug, Thanks for the opinion of Senior Editor Ed Perratore to add to that of Wind Power Expert Coy Harris. Coy never opined to me about the economics of the
          Message 4 of 26 , Oct 13, 2012
            Doug,

            Thanks for the opinion of Senior Editor Ed Perratore to add to that of Wind Power Expert Coy Harris. Coy never opined to me about the economics of the turbine, and Ed did not seem technically able to troubleshoot the anomalous output. Coy may have had a better install in a better wind location. Buildings can have serious dead spots in their wind field. There is also the independent rating

            I am still collecting information here. Why must you call me names for reporting Coy's opinion? We still need to explain how these two reports can be so divergent. I have not yet rendered my final judgement on this turbine, but hope it will be a model of excellence for you to aspire to,

            daveS
          • Doug
            Dave: You don t need to render a final judgement on this turbine, since you know nothing of wind energy and your opinion reflects complete ignorance. You
            Message 5 of 26 , Oct 14, 2012
              Dave:
              You don't need to render a final judgement on this turbine, since you know nothing of wind energy and your opinion reflects complete ignorance. You already have given your opinion, and there is no doubt about it: You know everything, I know nothing, everything I say is wrong, and every crappy joke of a turbine is great.

              When I said Professor Crackpot is like a wheelbarrow at a Formula-1 race I was not exaggerating: Consumer Reports agrees: half of one percent of the performance is a similar ratio to 200 mph vs 1 mph. You think what I say is hype - you have no idea.

              I called Coy in Lubbock, Texas yesterday. He told me the real story:
              The Honeywell turbine experienced a 50-60 mph wind soon after being installed, which immediately burned out its "controller".
              The Honeywell turbine system is not operational until they can replace this critical component. What do you think is gonna happen next time they get 50-60 mph winds?

              Like I have said, overspeed protection is not the main thing, it's the only thing. Why? Otherwise you will have a turbine that is not operational, which can therefore produce no power. We figured out long ago that you are better off with a turbine that produces a tenth of the power if it survives. In the case of Honeywell, it produces less than 1% of the advertised energy, AND it cannot survive even the first real storm.

              I asked Coy how much power it had made. He told me he had no information on power at all. They were just getting their collection of wind turbines all set up, and had no way to measure output yet.

              Coy related that their site has the same setup as two of my test sites: 48-Volt battery systems with Xantrex grid-tie inverters. He's planning on putting about 4 turbines through the same inverter. "Funny," I told him, "we are also just about to start trying to put more than one turbine through the same exact system".

              I've been a fan of this wind museum in Lubbock, Texas since I first saw it on the web several years ago, noting they had a side-by-side dual-rotor farm water-pumper windmill...

              Thanks for the intro.
              Just for the record, I have a SuperTwin(TM) mounted at 14 feet height on my van in the backyard that produced 4 kWh every afternoon using a couple of 2x4's as blades. So $5 of lumber produces as much energy in an afternoon as the Honeywell produced in a year and 3 months. Yes I'm sure having a bit of wind helps...

              I once took a 6-bladed Hornet wind turbine (5-foot diam, 20 lbs, $500) and carefully took a power curve, measuring 50 Watts at 20 mph. I replaced the six (6) factory blades with a single wooden 2-blade straight-thru rotor (a 5-foot 1x4 from Home Depot) and measured 100 Watts at 20 mph - I got twice the power just by mounting decent blades, and far fewer of them!

              I guess I could have tried cloth blades too, right?
              K gotta go.
              I hope I have shown that everything you have said abou everything I say being wrong is simply wrong.

              Keep up the fight for ignorance!


              --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
              >
              > Doug,
              >
              > Thanks for the opinion of Senior Editor Ed Perratore to add to that of Wind Power Expert Coy Harris. Coy never opined to me about the economics of the turbine, and Ed did not seem technically able to troubleshoot the anomalous output. Coy may have had a better install in a better wind location. Buildings can have serious dead spots in their wind field. There is also the independent rating
              >
              > I am still collecting information here. Why must you call me names for reporting Coy's opinion? We still need to explain how these two reports can be so divergent. I have not yet rendered my final judgement on this turbine, but hope it will be a model of excellence for you to aspire to,
              >
              > daveS
              >
            • dave santos
              Doug, When i askd Coy about the Honeyell he seemed to like it. He strangely did not blame the HW controller at that time, but we did not spend a lot a time
              Message 6 of 26 , Oct 14, 2012
                Doug,

                When i askd Coy about the Honeyell he seemed to like it. He strangely did not blame the HW controller at that time, but we did not spend a lot a time going into it.

                Thanks for digging deeper than your two-minute search for Consumer Reports. We now know both Honeywell and your turbines are subject to similar failure, but your emotional reaction is different depending on whose failure is considered.

                The wind tunnel error you mention is well known. That is why i am still wanting to run down that lead; to see what really went down with that test. This is not a "fight for ignorance", but a patient gathering of facts.

                Its still an open question if there is a performance intersection of ducted turbines and modern turbofan engines. We could reach high speeds with our turbines by sweeping them in fast wind, and the duct is favored operationally due to lower snagging risk, even though cost and weight seem to go the other way.

                Why don't you donate a Selsam machine to the mueseum?

                daveS

              • Doug
                Hey Dave S. Wrong wrong wrong. I have turbines at the most punishing sites possible, where big-name heavy-duty turbines lasted only months. You have stated
                Message 7 of 26 , Oct 15, 2012
                  Hey Dave S.
                  Wrong wrong wrong. I have turbines at the most punishing sites possible, where big-name heavy-duty turbines lasted only months.
                  You have stated unequivocally that the Honeywell Turbine is a good turbine. It is YOU who are wrong. You who make reckless statements based on knowing nothing of wind energy and being unwilling to learn.
                  Only idiots defend the Honeywell turbine. The real wind energy groups have been making fun of it for years. So, have at it, my good professor!

                  It is one more example of you knowing absolutely nothing about wind energy. There's only one reason you try to say the Honeywell turbine is good - because I tried to warn you it is bad, and you think it's your duty to refute every fact introduced to this group in your continued fight for ignorance.

                  It is only an ignorant person who could compare the Honeywell at hundreds of pounds, over ten thousand of dollars, with high-level corporate backing, that has been shown to be useless in the only two cases we've seen so far:
                  1) not enough wind
                  2) too much wind
                  Notice the pattern there? The turbine is still "perfect" even though it is shown to always fail, it is now "the wind's fault!"
                  Too much wind, too little wind - maybe all it needs is a "Little REd Riding Hood site where the wind is always "juuuuust right" Ya think? Then maybe it could make the 500 Watts or so a turbie of its size can be expected to produce. But of course the owner has still paid twenty times too much for a 500-Watt turbine.
                  You can't make this stuff up!

                  And you want to cite a corporate-sponsored, in-production turbine, with millions of dollars in PhD "work" behind it, millions of dollars in development and tooling, as "the same" as my prototype that, using two 2x4's from Home Deopt as blades, lasted a year in a windfarm, and which simply blew a $1 diode that was not even part of the turbine at all, just a randomly-chosen and disposable automotive rectifier that could be replaced anytime for ten bucks and a drive to Autozone.

                  Dave S., real wind energy systems can be forgiven for needing a small, easily replaced electronic part after a year of torture, but if you remember, it was just a prototype anyway.

                  You are comparing a machine that ran for a year, producing great power the whole time, in all wind regimes, to a machine that IMMEDIATELY shows it makes no power in light winds and cannot handle strong winds.

                  The Honeywell turbine is not alone - ALL professor Crackpot turbines are like that. You just don't know about it because all this is new to you, and you are seeing it for the fist time. Obviously you are naturally drawn to each losing idea, rather than seeing what works and going with it.

                  I need to stop wasting my time telling you anything since your fight for ignorance proves you do not like facts.

                  --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
                  >
                  > Doug,
                  >
                  > When i askd Coy about the Honeyell he seemed to like it. He strangely did not blame the HW controller at that time, but we did not spend a lot a time going into it.
                  >
                  > Thanks for digging deeper than your two-minute search for Consumer Reports. We now know both Honeywell and your turbines are subject to similar failure, but your emotional reaction is different depending on whose failure is considered.
                  >
                  > The wind tunnel error you mention is well known. That is why i am still wanting to run down that lead; to see what really went down with that test. This is not a "fight for ignorance", but a patient gathering of facts.
                  >
                  > Its still an open question if there is a performance intersection of ducted turbines and modern turbofan engines. We could reach high speeds with our turbines by sweeping them in fast wind, and the duct is favored operationally due to lower snagging risk, even though cost and weight seem to go the other way.
                  >
                  > Why don't you donate a Selsam machine to the mueseum?
                  >
                  > daveS
                  >
                • dave santos
                  In summary, my personal finding is the Honeywell turbine is over-claimed, over-engineered, and vastly over-priced. Its very unsuited for average sites where
                  Message 8 of 26 , Oct 15, 2012

                    In summary, my personal finding is the Honeywell turbine is over-claimed, over-engineered, and vastly over-priced. Its very unsuited for average sites where the most-probable-windspeed is well below its "ideal" wind.

                    Its low power-to-weight makes it unattractive for AWE, but the shrouded rotor format suggests a possible future direction for AWTs that operate in smooth strong high-altitude winds with caged rotors that prevent snagging on kite lines.

                    It no real mystery why Coy Harris, the top conventional windpower master of our circle, can still like a turbine like this, and share the fun with those like him. The Honeywell is like the infamous Edsel automobile, a sort of interesting odd-duck appreciated as a collectable. Doug and Paul Gipe are no less correct to point out the defects as they relate to the small windpower consumer. 

                    Doug is badly mistaken on one point- It seems no one besides promoters ever "stated unequivocally that the Honeywell Turbine is a good turbine."




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