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zqnwpu November 16, 2004 13:34

About low Reynolds number airfoil experiment data.
Hi: i need some low Reynolds number airfoil experiment data to validate my NS code,because i don't know if it is right for low RE flow, Where can I get some experiment data free? I have download some data about airfoil data( as UICC web-site),but there is no free stream Ma no. and temperature, May is there any other methods to test the code? Many advice will be great appreciated !


andy November 16, 2004 13:56

Re: About low Reynolds number airfoil experiment d
Low Reynolds numbers aerofoil flows are usually low Mach number and isothermal. For such flows the Reynolds number is the only significant parameter. The Mach number is zero and the temperature constant. The thermodynamic state would only affect the size of the (constant) density which is determined via the Reynolds number.

I am curious if you have an application for high Mach number and low Reynolds number aerofoil flows?

Jarmo Monttinen November 16, 2004 14:51

Re: About low Reynolds number airfoil experiment d
What is your Reynolds number?

I would not worry about the FS Mach number, if you have a compressible code, just set it to 0.1 that has been used by others successfully.

You might want to look at: Carmichael, B. H. 1981. Low Reynolds Number Airfoil Survey, Volume 1, Final Report. NASA CR-165803, Langley Research Center.

This will most likely explain why your results do not agree with experimental results.

-- Jarmo

zqnwpu November 17, 2004 00:19

Re: About low Reynolds number airfoil experiment d
Hi, Thanks Jarmo and andy! The Reynolds numer are baseed on the airfoil chord length,maybe 4*10**4,just as Jarmo said, I use a compressible code to simulate the flow field around A18 airfoil,from (,the data format reads: ..... Airfoil: A18 Builder: R. Cooney Comment: clean

Number of Reynolds #'s: 7

Average Reynolds #: 40000 Number of angles of attack: 7 alpha / Cl / Cd / S panwise Cd's >>> -1.16 0.117 0.0244 0.0247 0.0203 0.0290 0.93 0.324 0.0202 0.0155 0.0237 0.0253 2.82 0.540 0.0349 0.0363 0.0353 0.0396 5.05 0.842 0.0405 0.0350 0.0401 0.0471 .......... so, if i set Mach=0.1,i steel need the temperature to determine the molecular viscosity ! if i set the temperature to be any value (maybe 289K), is it right? other words ,such setting will not reduce the accuracy of simulating results?

Jarmo Monttinen November 17, 2004 15:54

Re: About low Reynolds number airfoil experiment d
Yes, go ahead and set M=0.1, and T = 288 K or so. This approach will give you a reasonable numerical approach.

But as you can see from the data, the cd varies along the span, so you are not likely to match the results using a 2-D simulation.

-- Jarmo

Jussi Salminen December 25, 2004 04:52

low Re-number airfoil experimetnt
Do you have any text / data available in pdf form?

Jussi Salminen, R&D Manager, Netma Progress Oy, Lahti Finland.

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