Air dynamic viscosity.
Air dynamic viscosity.
(OP)
Hi,
I've been searching on the web for air dynamic viscosity at different temperatures @ a certain altitude. There are plenty of calcs on the web for the dynamic viscosity at different temps, different altitudes but not both of them together. DOes anyone know of any?
Thanks in advance
I've been searching on the web for air dynamic viscosity at different temperatures @ a certain altitude. There are plenty of calcs on the web for the dynamic viscosity at different temps, different altitudes but not both of them together. DOes anyone know of any?
Thanks in advance





RE: Air dynamic viscosity.
In either case, the effect of altitude is to change atmospheric pressure. There are several correlations that do a decent job of converting altitude into a pressure. Once you have the pressure you are interested in, then something like NIST's REFPROP.EXE does a very good job of applying equations of state and estimating a viscosity.
David
RE: Air dynamic viscosity.
If there is anything else I have missed out or its still unclear please let me know I will try my best!
Zee
RE: Air dynamic viscosity.
Of course the altitude will have a significant effect on the density of the air, and the temperature will affect both the viscosity and the density.
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RE: Air dynamic viscosity.
If I remember correctly from my Compressible Flow class (nearly 20 years ago), Reynolds Number (and therefore the whole Moody paradigm) is not a significant factor in drag above about 0.6 Mach so this all gets really messy as you speed up way beyond what we see inside pipes.
David
RE: Air dynamic viscosity.
Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso
RE: Air dynamic viscosity.
Regards