A w:vortex street around a cylinder. This can occur around cylinders and spheres, for any fluid, cylinder size and fluid speed, provided that the flow has a Reynolds number between roughly 40 and 1000.Pressure dependence of the dynamic viscosity of dry air at the temperatures of 300, 400 and 500 kelvins
The viscosity of air depends mostly on the temperature. At 15 °C, the viscosity of air is 1.81x10−5 kg/(m·s) 18.1 μPa·s or 1.81x10−5 Pa·s. The kinematic viscosity at 15 °C is 1.4810x10−5m2/s or 14.8 cSt. At 25 °C, the viscosity is 18.6 μPa·s and the kinematic viscosity 15.7 cSt.