The viscous calculations depend upon the characteristics of the fluid. The user may select a specific Reynolds number in order to replicate published wind tunnel data, or as an option, select the free stream velocity, altitude, and chord to calculate the Reynolds number. All of the airfoil and atmospheric parameters are controlled by the slider bars or by manually entering the values.
The Reynolds Number, either free stream velocity, either chord length, and the altitude values may be entered by left clicking over the numeric value and typing the desired value in the text box.
The air parameters are given by the following relationships:
ρ = 0.00237689 (1 - 0.000006875347 Altitude)4.2561
Temperature = 59 - 0.00356616 Altitude
Viscosity = [(232.8999 (Temperature + 459.7)1.5) / (Temperature + 675)] 10-10
Mach 1 = [2403.0835 (59 - 0.00356616 Altitude + 459.688)] ½
Density is in slugs/ft3, altitude is in feet, temperature in degrees F, and viscosity in lb-sec/ft2