Search found 14 matches

by Irfan.Zafar
Tue Aug 20, 2013 5:39 am
Forum: Rotor Aerodynamics
Topic: Rfoil
Replies: 0
Views: 4354

Rfoil

Hi,
Does anyone in this forum is in possession of Rfoil and would like to share?
Many thanks,

Kind regards,
Irfan
by Irfan.Zafar
Tue Jun 18, 2013 1:29 pm
Forum: Airfoils
Topic: Data of Wortmann, FX airfoils
Replies: 1
Views: 8339

Data of Wortmann, FX airfoils

Hi,
I am looking for experimental aerodynamic data for Wortmann airfoils fx-w-343, fx-w-258, fx-w-218, fx-w-16. Does anyone have any information about it?
Thanks,

Irfan
by Irfan.Zafar
Mon Jun 17, 2013 12:24 pm
Forum: Airfoils
Topic: Coordinates of NLF 422 airfoil
Replies: 0
Views: 7241

Coordinates of NLF 422 airfoil

Hi everyone,
Can anyone please provide me coordinates of NLF 422 airfoil?
Many thanks,

Irfan
by Irfan.Zafar
Thu Aug 16, 2012 5:17 am
Forum: Airfoils
Topic: Questions regarding Airfoilprep
Replies: 4
Views: 9382

Re: Questions regarding Airfoilprep

I also use AirfoilPrep except dynstall sheet but I don't usually have much problems with it. What exactly is not clear? Can you re-phrase your question again, maybe I can answer it.

Kind regards,

Irfan
by Irfan.Zafar
Mon Aug 13, 2012 3:46 pm
Forum: Airfoils
Topic: Questions regarding Airfoilprep
Replies: 4
Views: 9382

Re: Questions regarding Airfoilprep

Wahed, I can answer some of your questions: 3D stall sheet : 3D effects are more significant near the root region (inboard part of the blade) and become less significant in the outboard part. You can check this by by using different values of r/R and you will notice as r/R becomes > 0.45 or so, the ...
by Irfan.Zafar
Wed Aug 08, 2012 3:31 am
Forum: Airfoils
Topic: Airfoils for 10 kW variable speed wind turbine
Replies: 3
Views: 9088

Re: Airfoils for 10 kW variable speed wind turbine

Dear Marshall, Thank you for your reply. Actually I already have looked at NREL airfoils but a license is required to use those airfoils, which is not an option for me now. So, I am looking for some suitable "free airfoils" for 10 kW variable speed, pitch regulated wind turbine blade (4.6 ...
by Irfan.Zafar
Thu Aug 02, 2012 12:52 pm
Forum: Airfoils
Topic: Low Wind turbine Aerofoil
Replies: 4
Views: 9398

Re: Low Wind turbine Aerofoil

Suni, The design approach for small wind turbines is same as for large wind turbines. BEM theory does not pose any restriction on the size of wind turbine so there is no difference in my opinion between small and large HAWTs. For low Reynolds number airfoils you can look at University of Illinois we...
by Irfan.Zafar
Wed Aug 01, 2012 3:21 am
Forum: Airfoils
Topic: Low Wind turbine Aerofoil
Replies: 4
Views: 9398

Re: Low Wind turbine Aerofoil

Suni, Desired airfoil characteristics depend on the type of wind turbine (stall regulated or pitch regulated, fixed speed or variable speed). But the general characteristics includes insensitive to roughness, high lift to drag ratio in the outboard part, smooth stall etc. Airfoils designed for high ...
by Irfan.Zafar
Mon Jul 30, 2012 7:16 am
Forum: Airfoils
Topic: Airfoils for 10 kW variable speed wind turbine
Replies: 3
Views: 9088

Airfoils for 10 kW variable speed wind turbine

Hi,
Can anyone recommend some airfoils (minimum 14% thick) for 10 kW variable speed HAWTs? The Reynolds number is in the range of 200,000 to 1 million.
I have examined SG 60xx airfoils but they are not insensitive to roughness.
Thanks,

Kind regards,

Irfan
by Irfan.Zafar
Tue Jul 10, 2012 12:58 am
Forum: Airfoils
Topic: Extrapolating drag coefficient
Replies: 3
Views: 8330

Re: Extrapolating drag coefficient

Dear Nguygen, Thank you for your reply. I have data up to about 15 deg AOA for an airfoil. To reduce uncertainty is it better to first use CFD to get data up to e.g. 27 deg AOA and then using some extrapolation method I can extrapolate data to 180 deg AOA or there is any other option? Can you please...
by Irfan.Zafar
Wed Jul 04, 2012 1:34 am
Forum: Airfoils
Topic: wind turbine blade optimization
Replies: 6
Views: 9005

Re: wind turbine blade optimization

Kar, For aerodynamic design optimization you can look at the book "Aerodynamics of Wind turbines" by Martin O.L. Hansen. Chapter 8 of this book explains the optimization procedure. With PROPID, you can do optimization. Chapter 8 (Design mode) of the manual describes how to do optimization....
by Irfan.Zafar
Thu Jun 28, 2012 3:12 am
Forum: Airfoils
Topic: Extrapolating drag coefficient
Replies: 3
Views: 8330

Extrapolating drag coefficient

Hello, I have a question regarding extrapolating drag coefficient. I have Cd data of an airfoil up to 12 deg, lift data is available up to 20 deg and the stall angle of the airfoil is about 15 deg. I want to ask if I extrapolate Cd from 12 deg using flat plate theory or some other method then would ...
by Irfan.Zafar
Tue Jun 19, 2012 5:14 am
Forum: Airfoils
Topic: Data for NREL Airfoils
Replies: 19
Views: 38843

Re: Data for NREL Airfoils

Hi, I am designing a blade of small stall regulated wind turbine of about 11 meter rotor diameter. Currently I am looking for suitable airfoils which I can use for the blade. S822 and S823 airfoils from NREL appear to be most suitable for this size of blade. Can anyone please clarify that in order t...
by Irfan.Zafar
Tue Jun 19, 2012 5:00 am
Forum: Airfoils
Topic: wind turbine blade optimization
Replies: 6
Views: 9005

Re: wind turbine blade optimization

You can use following tools for optimization:
1. WT_Perf (from NREL)
2. Propid (from University of Illinois)
Procedure for optimization is described in the manuals of these codes.

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