isaVisc

provides the viscosity of the ISA model.

This is simplifed method which calculates the viscosity nu in m^2/s.

The source for the curve fitting is https://www.engineeringtoolbox.com/international-standard-atmosphere-d_985.html

The data is fitted in three zones:

0km =< h =< 11km

11km =< h =< 20km

20km =< h <= 30km

The absolute error of the fitted functions are less than 2.5e-6, and less than 5e-3 for the rel. error.

For values of h smaller than 0m and larger than 30m the fitting function is clipped to the extreme values.

Usage:

nu = isaVisc(h);