First method of Chapman Enskog is available Here or at the end of this post.
Viscosity by Yoon & Thodos correlation
There are two things to remember - 1 Polar Gas, 2 Non Polar Gas.
So for Non Polar Gas the equation is -
Vis * zeta = 4.610 * Tr^0.618 - 2.04* exp(-0.449 * Tr)+ 1.94 * exp(-4.058 Tr) + 0.1
Tr = Reduced temperature with its usual definition i.e Tr = T / Tc
zeta is given by the following equation.
zeta = [Tc ^ (1/6)]/ [ M ^ 0.5 * Pc ^ (2/3) ]
So its more simpler than first method of Chapman & Enskog.
Now for Polar Gases there are two parts. One is for Tr Hydrogen bonding & second is non hydrogen bonding. The equations are -
For Hydrogen bonding gases, the applicability is Tr < 2.0
Vis x zeta = (0.755 Tr - 0.055 ) * [Zc ^ (-1.25)]
For Non Hydrogen bonding gases, the applicability is Tr < 2.5
Vis x zeta = [(1.90 Tr - 0.29 )^0.8 ] * [Zc ^ (-2/3)]
Zc = Compressibility factor at critical point, usually available.
zeta = is already given above.
Yes again the unit of viscosity here is micropoise.
List of other property estimation methods on this Blog.
- Calculate Diffusion Coefficient in Gases
- Calculate Diffusion Coefficient in Liquids
- Heat Capacities of dissolved solids & organic solutions - Quickest methods
- Heat capacities with dissolved solids
- Kinematic viscosity of air Vs Temperature
- Thermal Conductivity of air Vs Temperature
- How to calculate viscosity of liquid mixtures
- Surface Tension
- Viscosities of Pure Gases at Low Pressure - 1