How this calculator works
Sutherland law approximates the temperature dependence of dry-air dynamic viscosity at low pressure. Dividing by density gives kinematic viscosity. Density comes from the ideal-gas relation, which can also be solved for the other state quantities. Changing the gas constant only changes that density relation; the viscosity constants remain those of air. This tool limits temperature to 170 through 1500 K and pressure to two atmospheres. It does not model dense gas or a different chemical composition.
Formula
mu = 1.716e-5 (T/273.15)^1.5 (273.15+110.4)/(T+110.4) Pa s; nu = mu/rho; rho = p/(R_s T).
Worked example
At 273.15 K the reference dynamic viscosity is 1.716e-5 Pa s. At unchanged temperature, halving pressure halves density and doubles kinematic viscosity.
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Frequently asked questions
How do dynamic and kinematic viscosity differ?
Dynamic viscosity describes shear resistance; kinematic viscosity divides that resistance by density.
Does the custom gas constant select another gas?
No. The Sutherland coefficients still represent dry air.
How do I convert m2/s to cSt?
Multiply by one million to express m2/s in centistokes (cSt).