Calculating reference variables
 

Can someone explain how reference velocity and viscosity are defined? Why free-stream values are not being used?

Here's copy of output from SU2.
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-- Input conditions:
Specific gas constant: 287.058 N.m/kg.K.
Free-stream pressure: 111502 Pa.
Free-stream temperature: 303 K.
Free-stream density: 1.28195 kg/m^3.
Free-stream velocity: (13.8, 0, 0) m/s. Magnitude: 13.8 m/s.
Free-stream total energy per unit mass: 217542 m^2/s^2.
Free-stream viscosity: 1.86008e-05 N.s/m^2.
-- Reference values:
Reference specific gas constant: 287.058 N.m/kg.K.
Reference pressure: 101325 Pa.
Reference temperature: 303 K.
Reference density: 1.16494 kg/m^3.
Reference velocity: 294.921 m/s.
Reference energy per unit mass: 86978.6 m^2/s^2.
Reference viscosity: 343.566 N.s/m^2.
-- Resulting non-dimensional state:
Mach number (non-dim): 0.0395466
Reynolds number (non-dim): 35000. Re length: 0.0368 m.
Specific gas constant (non-dim): 1
Free-stream temperature (non-dim): 1
Free-stream pressure (non-dim): 1.10044
Free-stream density (non-dim): 1.10044
Free-stream velocity (non-dim): (0.0467921, 0, 0). Magnitude: 0.0467921
Free-stream total energy per unit mass (non-dim): 2.50109
Free-stream viscosity (non-dim): 5.41403e-08
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EDIT: Figured out from source code. vel=f(p,rho), visc=f(rho,vel,ref_len)

You can find some useful information in
http://su2/documents/SU2_AIAA_ASM2013.pdf

Best Regards,
Francisco Palacios
SU2 lead developer