The kinematic viscosity ( 'nu') is the dynamic viscosity of the medium divided by its density. Relationship between dynamic and kinematic viscosity v. Dynamic viscosity increases for gases as temperature rises. Other data sources may make different choices. The dynamic viscosity drops off very quickly for liquids as their temperatures increase.
For example, ESDU 80025 provides curves relating drag and lift coefficients to $\Reyn\flow$.
The key factor is that the method chosen matches the source of the variable drag and lift coefficient data. Which $\Reyn$ option you choose is, to a large extent, arbitrary. Reynolds number is itself available as a line result. These three options are all related by $\Reyn\cross/\cos\alpha = \Reyn\nom = \Reyn\flow\cos\alpha$, from which it follows that $\Reyn\cross \leq \Reyn\nom \leq \Reyn\flow$. or, SI Units of Kinematic Viscosity kg./ms / kg/m 3 or, SI Units of Kinematic Viscosity kg. Note that the division by $\cos\alpha$ means that $\Reyn\flow$ can be arbitrarily large when the relative flow is very near axial: this turns out not to matter, since the normal component of relative velocity is then very small, so the resulting drag and lift forces are also very small.
