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REYNOLDS NUMBER!!!

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Old   November 1, 2006, 09:31
Default REYNOLDS NUMBER!!!
  #1
Sze Hong Ng
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ok here is my problem, ive got to simulate the shockwaves over a NACA 0012 at mach 0.8 my problem resides in that basically i cannot find any documents which state Reynolds number, rho,u,l and mu to reference my stuff from I cant even start the project. Every report ive searched for states a Re and maybe 1 other parameter but nothing else! Please help me or tell me what are the benchmarks to start any flow simulation of a NACA 0012 from.

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Old   November 1, 2006, 11:29
Default Re: REYNOLDS NUMBER!!!
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ag
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I don't understand your post. You say that you can't find documents giving Reynolds number, but that every report you've searched states Reynolds number. Assuming that you do have a Reynolds number and Mach number, then pick a temperature (atmospheric tables can be used if you want to simulate a particular altitude - this will also give you a density). Use the temperature to compute speed of sound, and use that to compute free-stream velocity. The temperature also gives the viscosity, if you use Sutherland's law or the power law. The length scale you choose depends on what you used to non-dimensionalize your equations of motion.
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Old   November 2, 2006, 07:47
Default Re: REYNOLDS NUMBER!!!
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Sze Hong Ng
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ok, what i meant was basically that i need to validate first CFX. I have the wing ordinates of a NACA0012, i need to test the wing at sea level, therefore i know the values of rho, u and mu. but i still have one value which im missing, Re and/or l the thing is that I need to know basically the reference wing chord length that people usually use, my lecturer tolme that it should be around 0.2...m but he's not sure.
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Old   November 2, 2006, 08:49
Default Re: REYNOLDS NUMBER!!!
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ag
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If you have the coordinates of the wing, then you have the chord length of the airfoil. Why not use that?
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Old   November 5, 2006, 19:35
Default Re: REYNOLDS NUMBER!!!
  #5
F.B.Tian
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you can try this: Re=sqrt(\gama R T_0)Ma*D/(\niu)
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