Unlike liquids, gas viscosity with temperature. Perry’s frequently cites Sutherland's Formula for these predictions:
is in Kelvin. For many common hydrocarbons, simpler forms like are provided. Perry's Handbook Viscosity
Liquid viscosity drops sharply as temperature rises. Perry’s often utilizes a variation of the : Unlike liquids, gas viscosity with temperature
While simple fluids use standard definitions , Perry’s relies on specific models for temperature dependence: For Liquids Perry's Handbook Viscosity