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Beth Stackpole
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Preference for wind tunnel not simulation?
Beth Stackpole   5/24/2012 7:46:24 AM
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I totally understand the criticality of analyzing airflow to make tweaks to the car that will deliver a competitive edge. But what about employing 3D simulation software as opposed to or in addition to physical wind tunnel testing. Wouldn't simulation testing be easier and less expensive than putting the cars through their paces in physical wind tunnels? Do they not have the technology or are there specific reasons why the physical world still has an edge in testing at this stage of game?

naperlou
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Re: Preference for wind tunnel not simulation?
naperlou   5/24/2012 9:29:07 AM
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Beth, in my experience, and that of others I talk to, the setting up of a model is very difficult and time consuming.  This is especially true of something like an Indy Car.  Considering the time between races and the ability to simulate the track with a device, it might be quicker to do it this way.  On the other hand, when designing a large complex machine or one that will be made in large volume, the time is worth it. 

Charles Murray
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Re: Preference for wind tunnel not simulation?
Charles Murray   5/24/2012 7:32:31 PM
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I believe they do use computational fluid dynamics in addition to, and in conjunction with, their wind tunnel time, Beth.

bwilson4web
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Gold
Time for a Google-driver, race car
bwilson4web   5/24/2012 10:41:19 AM
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Perhaps after getting driving rights for their autonomous cars, Google might look at autonomous race car operation. Machine accurate, faster-than-human measurements in all directions and consistent operation, it might provide an interesting man-vs-machine contest. If nothing else, the machine operated car could remove human support systems along with the human. The vehicle could operate closer to the limits.

UAVs have already revolutionized military aviation. Almost every other week or so, UAV launched missles attack our enemies in Pakistan and Yeman. The robot warrior is becoming a fact, at least in the air.

Bob Wilson

Rob Spiegel
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Re: Time for a Google-driver, race car
Rob Spiegel   5/24/2012 3:50:41 PM
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That's a very good point, Bob. If all of the variables the driver faces could be identified, they could also be optimized. The lag time between an event and a response would be quicker with a computer. That coule make all the difference.

Charles Murray
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Re: Time for a Google-driver, race car
Charles Murray   5/24/2012 7:35:19 PM
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Some day, that could happen, Rob. The problem with autonomous driving right now is so-called "rogue vehicles," i.e., cars driven by humans. Autonomous cars have trouble predicting the crazy things that humans do. If we could get all the humans off the course, I think it could happen.

TJ McDermott
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Re: Time for a Google-driver, race car
TJ McDermott   5/25/2012 12:44:44 AM
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I don't think a robotic race would draw the crowds though.

Walt
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Gold
Re: Time for a Google-driver, race car
Walt   5/25/2012 9:36:02 AM
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At some point, it might be quite an interesting exhibition to have one or more top racers pitted against something like Watson - as Jeopardy did.

jmiller
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Platinum
Re: Time for a Google-driver, race car
jmiller   5/29/2012 8:34:09 PM
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I agree.  Going away from the human element would decrease crowd size as well as make things too automated.  Part of the fun of racing is watching someone take a risk that a computer wouldn't take and succeed causing them to win the race. 

In quite a few races the difference between winning and losing is knowing how much gas is left in the tank and often that is a little bit more than an educated guess.  But not much more.

Rob Spiegel
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Re: Time for a Google-driver, race car
Rob Spiegel   5/25/2012 10:42:27 AM
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A field of only autonomous cars may happen some day, Chuck. That would certainly showcase the quality of the inidividual vehicles. Remote control might be an option as well.

ChasChas
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Platinum
Re: Time for a Google-driver, race car
ChasChas   5/25/2012 10:34:35 AM
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Not idiocy at all, Architect. Simulation is used as design shortcuts, not as final solutions. It works well to get to the finer tuning stage - then real life comes to play.

The wind engine is still a "pie in the sky" - it can't earn its own keep - even after the billions spent on research and pilot projects. It can't pass "real life". You can only "bang your head on the wall" for so long.

Don't be questiong the ethics of a noble profession because it cannot perform miracles.

Jerry dycus
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Gold
Re: Time for a Google-driver, race car
Jerry dycus   5/25/2012 3:42:06 PM
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 Chaschas you sould do a little research as windgenerators do earn their keep and profits nicely.

Please don't confuse the finacial vehicles known as wind farms with whether wind is viable.  Facts are in many places wind is the low cost energy source and those using it are paying lower costs.  A recent utility study forcast that wind in the mid to west will keep the cost of electricity down.  Afterall it only takes 2kw of wind generator to power an eff home and tetail they are going for $2k/kw in larger sizes.

Facts are now solar PV,  Solar CSP/CHP,  wind are all now under $2k/kw or will be soon.  At that pricepoint it's less costly than retail coal.

As for Indy Aerodynamics it's mostly used for downforce and using hp to overcome the large aero drag it causes.  It's a very hard thing to design because things like paint lines have brought down airplanes and air coming out sideways from the racecar, etc create all kinds of problems.

I depend on weight, low CG to keep me stuck to the earth and just use aero to lower drag to increase range.

ChasChas
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Platinum
Re: Time for a Google-driver, race car
ChasChas   5/25/2012 4:02:53 PM
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You're probably right, Jerry. I've read mostly about farms. The private sector always does it better. Private power seems to be making good headway.

In general, when names and character assassination are used, I suspect poor facts.

ChrisP
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Silver
Re: Time for a Google-driver, race car
ChrisP   5/25/2012 5:04:02 PM
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How can you say that it cannot earn its own keep when there are many profitable wind farms?

Walt
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Gold
Re: Time for a Google-driver, race car
Walt   5/25/2012 10:41:16 AM
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Bill (Architect), I won't disagree that "the way we've always done it" often wins out over creativity and methodology and I'm also no aerodynamic expert, but I would argue that such an exhibition like that of Watson could help fund research that would potentially benefit millions of people...

ChasChas
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Platinum
Re: Time for a Google-driver, race car
ChasChas   5/25/2012 11:32:41 AM
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This is interesting, Architect. My question remains "Will 39% percent increase in efficiency make the difference?"

The wind doesn't blow all the time and there are other issues.

Sorry, all! I went off track here. 

Lyngengr
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Iron
Aerodynamics have ruined racing
Lyngengr   5/25/2012 12:21:30 PM
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This article just underscores how much aerodynamics have created parades rather than races.  With the incredible emphasis of creating a car that can be driven flat out all the way around Indy, driver skill is secondary.  If you look at an Indy or F1 car there are all sorts of wickers, splitters, trim tabs, diffusers, flaps, etc. designed to keep the car glued to the road with minimal drag.  Unfortunately this creates unpredictable handling when running close to other cars so there is no way to pass unless one car is a lot faster (i.e., less drag) than another.  I would really like to see substantial limits on aerodynamics, including an outright ban on wind tunnel testing, so that driver skill and the ability to pass are brought back into racing.

jmiller
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Platinum
Re: Aerodynamics have ruined racing
jmiller   5/29/2012 8:38:30 PM
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I agree that some of the aerodynamics improvements have made racing less exciting.  However, I think technology has also made racing more exciting.  I disagree a little bit with this article because it focuses so much on aerodynamics.  There is so much more to racing.  I am in awe that taking 1/2 pound of air out of the left front tire can really make that much of a difference in how the car drives.  But it does.  Absolutely awesome.

ChrisP
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Silver
They all use the same Dallara body?
ChrisP   5/25/2012 5:06:05 PM
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Why is this post relevant?

bobjengr
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Platinum
INDY AERODYNAMICS
bobjengr   5/25/2012 5:26:37 PM
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Charles—Fascinating article!  OK, the first time I have heard the word "wickers" in my life—first time.  You mention in your write -up that KV spends considerable time with trial and error before settling upon a suitable design that gives optimum performance.  I recently published an article on the Sim Center located within the University of Tennessee at Chattanooga facilities.  This center performs computational engineering analysis on air flow ( and other things )around the "big rigs"; eighteen wheelers fully loaded and going coast to coast.  This is a remarkable technology and certainly one not existing when I was in engineering school.  Maybe the folks at KV could gain additional insights and reduce the time to  launch with this approach.  Again—great article.

Charles Murray
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Blogger
Re: INDY AERODYNAMICS
Charles Murray   5/25/2012 6:05:09 PM
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Thanks, bonjengr. It's surprising how important those wickers have become. IndyCar's rules are so confining that teams now spend thousands of hours working on details -- such as wickers -- to distinguish themselves.

Jerry dycus
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Gold
Re: Time for a Google-driver, race car
Jerry dycus   5/26/2012 7:19:41 AM
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  Yes Bil was either lying or just plain wrong.  I design, build windgenerators among other things, presently doing 2  2kw designs for production.

And mine will hit 35-40% eff, not 20%

Facts are the best wind power collectors are 3 blade rotors like you see on most all cost effective WG's.  As more blades are added they just interfer  with the ones before it  and add drag, lower tip speed needed to make real power.  Basic physics, deal with it and stop making ill informed statement.

Do you know why there is a Belt's limit?    Air flowing to a WG if too much energy is taken, the wind slows down in front of the WG rotor and goes around it instead.

I've done every type of WG including fast 20-30mph  sailboats and physics holds well on all of them.  Sadly means any WG with more than 5 blades just isn't going to be eff, cost effective.

If you think Bill's WG is so good build them and make a fortune.  Until you build and prove your points it's just misinformed vaporware or just a plain scam.  

jmiller
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Platinum
Re: Time for a Google-driver, race car
jmiller   5/29/2012 8:43:15 PM
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I bummed because I can see about 40 of these windmills on the horizon and just the other morning when it was very windy they were all sitting there not spinning.  The fact is there was plenty of energy there.  But the inferstructure to be able to store and use this energy is just not in place.

I can't wait until engineers are able to find the way to store and continue to make this technology more efficient and more profitable.  I know it will be a while before engineers are able to conquer some of the larger problems with the system.  But I can't wait.

William K.
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Platinum
aerodynamics and Indy cars, and other things.
William K.   5/26/2012 5:17:46 PM
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Steamlining, or reducing the airflow drag, is certainly the best way to get "free horsepower" for racecars. IT^ does get complex when there are multiple cars close together, though. Drafting is a bit different, it works for most cars on the road. We proved that back in 1967, using vacuum gauges to measure "effective engine load", which was a lot cheaper than an air tunnel or dynamometer. The problem with doing experiments on the local interstate is the way other folks get so upset at seeing two cars six inches apart. But it is safer than you might think, because if the front car slows quickly the second car catches up quickly and so the impact is quite small.

The number of blades on the big wind turbines is the result of a compromise that includes cost and weight, rather than being based just on maximum energy recovery. Otherwise they would have more blades.

Reducing the drag on "big trucks" is a very valuable effort because of the large number of them around. I am waiting for somebody to try air dams on the trailers and some sort of means to avoid the high-vacuum turbulence that I see behind the trailers. I have thought for some time that lowering the box three feet could do a lot to reduce the drag, but there are a lot of other considerations, it turns out. BUt I have seen a lowered tanker truck and it did look a lot more stable than the standard ones. IT would be very educational to hear what the research folks have come up with relative to steamlining trucks. After all, even a 1% reduction in fuel consumption would save a whole lot of money.

Jerry dycus
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Gold
Re: Time for a Google-driver, race car
Jerry dycus   5/29/2012 10:15:04 PM
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Architect,    Just because one is good in one area doesn't mean they are good in others.

Yes I know exactly the difference between a spinnaker and a mainsail. One is eff and the other isn't. Guess which one isn't?   PS I design, build 25knot cruising sailboats, live on, race and cruise them.  And on them a classic spinnaker isn't useful because they go faster downwind by tacking from one broad reach to the others allowing a high apparent wind going so much faster even with the extra distance.

The only reason a spinnaker works on a monhull well is it's so slow.  My Cats, Tri's are 4x's as fast so only special lift, not drag spinnakers are used.

As an illistration I once sailed a Mega 30 monhull but fast  though a racing fleet like I had my own private wind. How is the wind was about .5mph out of the aft quater/broad reach. I caught it, not easy and slowly pulled in the sails tighter which increased over the deck windspeed/apparent wind.  As the boat went faster, about 1mph added to the wind speed made it go faster. I got it going about 2mph that way while all the other boats sails just flopped around from the waves.  Guess which ones had spinnakers up?

Fact is drag is just that.  At low blade speed of a drag based  fan just can't extract much power because it resists!!!  Because of this resistance you are so proud of the wind mostly  just goes around the rotor.

     Vs a low blade/area ratio/2-5blades, allows the wind to go through easily, more of it and faster.    Without all the air friction and blade interference drag of a many bladed rotor the blade can go many x's the windspeed at the outside end allowing it to work in 100=300mph winds to extract power.  Vs just the windspeed for the drag style.

Please put up the specs, more info but basic physics, what I use to judge everything, it doesn't look good for Bill.

For referece eff for 2 blades about 48%, 3blades, 56%, 4 blades 42%, 5 blades 38% IIRC and eff drops off from there.  The Fan type used for pumping water is less than 10% eff.  They do it on purpose so it survives high winds better and just need torque to pump a little water so eff doesn't matter much as ruggedness.

If it's so good why don't you build it and make a fortune?  Put your money up like I'm doing.

Jerry dycus
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Gold
Re: Time for a Google-driver, race car
Jerry dycus   5/30/2012 11:15:42 PM
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 Either put up the data, details other than the vague claims you make or you have no case.

Again if it's so good why don't you do it?

The rest of the mostly garbage comments I'll ignore.

And I do all the time things that others say can't be done.  But I also have the smarts to see bad data without proof.  So put it up.

Jerry dycus
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Gold
Re: Time for a Google-driver, race car
Jerry dycus   6/3/2012 9:37:48 PM
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 Architect,

             The fact almost all windgens are 3blade is my proof. 

              Most of your statements show a lack of understanding basic science and you put up not even pics of your supposed great windgen.   Windtunnel?  I never mentioned one.

              I'm just starting my new design so don't have pics. But Mine doesn't matter as what you described can't complete with any decent  2-5 blade WG.

            It's you making wild claims so show us the data. I've put up mine, the industry 3 blade standard because they work best for  ROI.  Where is your data other than spurious claims?

             So no more from me on this, good luck as you'll need it. 

                                                      Jerry Dycus

 

 

Jerry dycus
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Gold
Re: Time for a Google-driver, race car
Jerry dycus   6/4/2012 3:35:19 PM
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     Hi Acrhitect,

               Finally real info.  I remember it from when he did it and yes it's an improvement on full fan turbines but still isn't as anywhere near  good as a standard 3 blade unit.

            2 things stand out he used a windtunnel which is known for giving false readings   like this from wall interference preventing the aiir from going around the turbine with so many blades.  Yes when he removed blades it went better because they let more air through.

            The other is flat blades. Sorry but just not going to cut it aerodynamically.

             Some people are easy to fool it seems. Like I say just put physics to work if you want to know what is fact or fiction or in many cases like this, not quite knowing how to do wind tunnel testing.  This problem has come up recently in serveral cases.  The windtunnel needs to be 4x's the size of the windgen and even then there are effects.

           

Jerry dycus
User Rank
Gold
Re: Time for a Google-driver, race car
Jerry dycus   6/4/2012 3:35:28 PM
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     Hi Acrhitect,

               Finally real info.  I remember it from when he did it and yes it's an improvement on full fan turbines but still isn't as anywhere near  good as a standard 3 blade unit.

            2 things stand out he used a windtunnel which is known for giving false readings   like this from wall interference preventing the aiir from going around the turbine with so many blades.  Yes when he removed blades it went better because they let more air through.

            The other is flat blades. Sorry but just not going to cut it aerodynamically.

             Some people are easy to fool it seems. Like I say just put physics to work if you want to know what is fact or fiction or in many cases like this, not quite knowing how to do wind tunnel testing.  This problem has come up recently in serveral cases.  The windtunnel needs to be 4x's the size of the windgen and even then there are effects.

           



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