Author Topic: airfoilprep  (Read 2119 times)

0 Members and 1 Guest are viewing this topic.

Zephyros

  • Newbie
  • *
  • Posts: 1
airfoilprep
« on: November 12, 2005, 03:13:41 PM »
Hi, I'm working at my Master dissertation. The main

objective of the work consists in making the study of the aerodinamic

performance of a small power wind turbine (1Kw), making use of the

AeroDyn/yawDyn programs and if possible, built a prototype to compare the

results achieved from the software with the ones measured from the  machine

operation.


At the moment, the problem I'm facing is that I would like to use the airfoil

FX 63-137 (smooth) and I'm not understanding how could I create the file for

this airfoil, so that the AeroDyn program can read it. I also tried to use Airfoilprep, but I really don´t no how to get does x and y values!


If  you could please help me solving this problem I would be very thankfull.

« Last Edit: November 12, 2005, 03:13:41 PM by (unknown) »

wdyasq

  • Hero Member
  • *****
  • Posts: 1324
Education....
« Reply #1 on: November 12, 2005, 05:15:37 PM »
First, let me get this straight. You are working on your MASTER's and you are asking free-lance amatures HOW to just draw the airfoil.


Not being familiar with the AeroDyn program I can only guess it has similar problems to other airfoil programs as the GAWDs who all claim to be expurts never saw fit to have a standard format for the airfoils to fit their program.  As the GAWD that wrote the program promotes his as superior to the sub-gawds that through ignorance wrote the format where it won't fit the superior GAWDs program, one must figure out WTF format the GAWD wants.  As the inferior sub-gawds probably have airfoild programs that would work, one must be acreful and not emntion using ne of the older, proven programs lest one upset the GAWD/gawd ratio.  (hint, sometimes airfoil coordinates are written trailing edge, lift side forward to leading edge then back to trailing edge in an x, y format.  Sometimes the gawd puts a 'zero-lift angle' line in it that must be removed and some gawds went trailing-edge to leading edge then started the bottom side back and went forward just to keep the water muddy.)


One will notice that once the airfoil is modeled those X, Y, and Z coordinates used to model cannot be used to build the actual file to cut the prescribed object until it is translated by a good CAD artist, converted to a cutting file by a second specailist and then cut by a third.  This is to give the GAWD a reason the object he described did not work as he claimed it should.  


It is my opinion this is done by design rather than ease of operation and standardization.  The idiot professors and experts would be out of work if they had to guarantee the drivel they spew was the truth or actually produce a worthwhile product that actually could be made as designed.


Ron

« Last Edit: November 12, 2005, 05:15:37 PM by wdyasq »
"I like the Honey, but kill the bees"

maker of toys

  • Full Member
  • ***
  • Posts: 221
Enough, already!
« Reply #2 on: November 12, 2005, 09:07:56 PM »
Ron-


(i'd have sent this to your e-mail, but I am not in possession of your address.)


I come here to try and learn. I have the expectation that when someone replies to a specific question, they either have potentially useful information to impart or some entertaiment to share.  Often, you have added to the pool of knowlege here that makes this board such a delightful and useful place to spend time.  One example of such is your Rhino model of the Lakota blade. Nicely done, and given with a generosity of spirit that does you credit.  


BUT:


If you don't know the answer to someone's question, is it too much to ask that you say so, in as many words? And, in cases where people ask basic questions, could you, PLEASE, refrain from a terse and curmudgeonly "search the board" reply?


 I can't see that your habitual negativity is doing the board any favors, and it certainly is not helping the renewable energy community put its best foot forward.


I, for one, don't appreciate it.


please desist.


thank you.


-Dan


 at yahoo: steel nomad 2002 (no spaces)

« Last Edit: November 12, 2005, 09:07:56 PM by maker of toys »

wdyasq

  • Hero Member
  • *****
  • Posts: 1324
Re: Enough, already!
« Reply #3 on: November 12, 2005, 09:50:05 PM »
Dan,


In the second paragraph is what I have found about airfoil programs - they are inconsistant as are the ways they are described.


The question was answered - inadequate data was given.  


I, for one, have a low tollerance for dealing with stupidity.  The best thing a lot of the folks who wander in here could do is be locked in a rubber room so thy won't hurt someone with miss-designed equipment and improperly hooking up things to a shared elecrical system.


There is a good reason few have a valid e-mail address for me.  When questions are answered there are usually a pile of emails from folks who don't need information, they need to learn how to read, use a library, use a search engine and a lot learn how to write cohesively.


The question was 'how to get the information in'.  There is no format other than x and y given.  WTF can't these highly educated, government paid (read that my tax dollar), technobozo professors follow a consistant pattern so the ignorant, uneducated masses who pay their saleries can use what we have paid for?


Ron

« Last Edit: November 12, 2005, 09:50:05 PM by wdyasq »
"I like the Honey, but kill the bees"

maker of toys

  • Full Member
  • ***
  • Posts: 221
Re: Enough, already!
« Reply #4 on: November 12, 2005, 11:11:22 PM »
at least as much blame for the proprietary format situation can be laid to the feet of the private sector folk who want to protect their little empire from some perceived threat to their profits. . . . make a file format (or a geometry decriptor) that is unique, and you create a 'company store' situation; once someone buys your software, he's stuck with whatever you give him unless he's willing to throw away a bunch of work and start over in someone else's company store.


and when some company signs up for a tax writeoff by 'donating' a software package to a school, often the profs are then contractually obligated (by the terms of the donation) to teach it. . . . perpetuating the company store.  And, when your tax dollars are spent to purchase a software package, your freindly legislator often cuts the funding for maint and upgrades  (by not mandating a cut in administrative costs, but instead making unfunded mandates about what (and how) things will be taught) so the software package is quickly out of date.


the solution? Open source.  Like this board;  it's open source hardware. So please don't muddy the waters for people who are at least willing to learn. . . . the ones who have the courage and the forsight to ask questions when they don't know the best way to tackle something.  the ones that are truely a danger are the ones that are so sure they know everything that they refuse to ask.  the Darwin awards are full of them.  


I went to school with people aspiring to be automotive engineers who had never changed their own oil.  I am sad for those people.  I am sad for the people who will drive and repair the products my classmate designs.


yes, there are people who would be better off not trying the things that get discussed here.


Infants probably would be better advised not to learn to walk, either;  the process is painful to them, annoying to others (who have to listen to the bawling) and even more frustrating because there's no-one to ask and no owners' manual to read.  But infants learn to walk anyway.  And they're better for the experience.


I certainly shouldn't have taken my first engine apart; Now I restore steam locomotives for a hobby.


my first electronic project started a fire because I didn't know how to tell when the PC board was etched sufficiently and the kit didn't mention anything about it; Now I build scientific prototypes for a living.


my first foray into reloading probably should have cost me a finger (at the least), but it didn't. . . . and now I have respect for chemical energy in all its forms.


I learned from each situation, and now I find myself moderately well equipped to survive as a tool-making life form.


I'm going to go out on a limb and guess that not all of your projects have adherred  to careful planning and strict safety guidlines, either.


Yes, there are people who are not tool users, and never will be.  those people don't ask questions on BBSs like these; they watch sitcom reruns instead. they complain about gas prices on their cell phone while they sit in the parking lot with the engine running in their SUVs so the heater still works.


yes, people could be better spellers, and use better grammar. there are very few english/engineering double majors. anyone else can be expected to make the odd mistake (and some even ones, too. . .)  the rest of us deal with it.


so, I encourage people to ask silly questions.  better to annoy me with the question than annoy me by doing something silly because noone told them what they needed to know when they asked. Better a stupid question than a stupid mistake. As you point out, stupid actions can hurt more than the stupid person in question.  I haven't heard of anyone being hurt physically by being asked a question.

'Nuff said.


to business:


the question was answered, I agree.  but the answer was so buried in your rant that I skipped over it looking for useful information instead of negativity.  I submit that you thereby defeat your own purpose.


and someone who asked a specific (if maybe insufficiently explained) question out of frustration with the same problems you so eloquently decry now has a slightly diminished opinion of amateurs and renewable energy hobbists. That someone might someday be in a position to do something about a situation that has you disgruntled.  That someone might someday be in possession of information that I could use.  But now, I doubt we'll see them again.  They'll certainly think long and hard before asking any more annoying questions here.


Thanks.


-Dan


(And I was not assessing blame or taking offense to not having your e-mail address;  I imagine you are happier knowing that you'll not get the likes of me berating you via e-mail, and that's certainly a valid arguement in my book.  you'll notice that I don't post mine in my message headers, either. . . .  In this case, I posted mine in case you wanted to take this private.  Obviously not.)


Note to Editor:  there will be nothing further from me on this subject.

« Last Edit: November 12, 2005, 11:11:22 PM by maker of toys »

rotornuts

  • Hero Member
  • *****
  • Posts: 537
Re: airfoilprep
« Reply #5 on: November 12, 2005, 11:24:45 PM »
Trailing edge over lift side down around underside and back to trailing edge for the Wortmann profile. Cut and paste the .dat file from NASG to notepad and input X,Y or Z in front of the co-ordinate columns depending on the desired view. 2D, X and Y. 3D, Y and Z and your on your own for the X values and twist and cord reduction etc. As for importing a text file to your particular program...?


This is what I've done for creating G codes and it works for my software. But I'm still stuggling to get past creating the part profile for the upper side. Must be some repetitive cycles I'm missing. Still trying to fiqure out if sub-routines are what I'm looking for? No way in .... I'm inputing every single co-ordinate. That's all I have to offer but it seems a shade more usefull that what's been offered so far.


Mike

« Last Edit: November 12, 2005, 11:24:45 PM by rotornuts »

rotornuts

  • Hero Member
  • *****
  • Posts: 537
Re: Enough, already!
« Reply #6 on: November 12, 2005, 11:33:51 PM »
Nicely put Dan.


Mike

« Last Edit: November 12, 2005, 11:33:51 PM by rotornuts »

monte350c

  • Full Member
  • ***
  • Posts: 228
Re: airfoilprep
« Reply #7 on: November 13, 2005, 03:26:57 PM »
Try:


http://www.profili2.com


Lots of foils in the library. Uses X-Foil for the analysis. Blended foils, compare CL/CD, at various alpha. Outputs to DXF - pay version.


This is an interesting program and doesn't require a "doctorate" to run.


Ted.

« Last Edit: November 13, 2005, 03:26:57 PM by monte350c »