Hello
in fact during my research, i found a (sutheland's law) allowing to calculate the viscosity of gases at high temperature, but in this formula appears coefficients (B and c) which empirical coefficients of the formula, i could have these coefficients for air, i would like to have these coefficients for the following gases: nitrogen (N2) water vapor (H2O) carbon dioxide (CO2). thank you for your attention
Look at https://doc.comsol.com/5.5/doc/com.comsol.help.cfd/cfd_ug_fluidflow_high_mach.08.27.html
Thank you for your answer. It gave me the answer for all the gases I need, except for water vapour.
https://doc.comsol.com/5.5/doc/com.comsol.help.cfd/cfd_ug_fluidflow_high_mach.08.27.html also contains steam, which is hot water vapour!
Further to Claude-Alain's response - are you looking for viscosity versus temperature at atmospheric pressure or viscosity at elevated pressure? Sutherland's method is OK for pure components at low pressure. Fig 3 in the GPSA Engineering data book is graph of low P viscosity for your components of interest. For mixtures and/or higher pressures, 'The properties of Gases and Liquids' - by Poling, Prausnitz and O'Connell section 9 describes 6 methods for prediction of pure and mixed gas viscosities as a function of T and P - generally using corresponding states methods.
Ulrich Nzemo Nketcha gas viscocity can be seen in the formula mentioned below for your reference
Sutherland's law, which is also known as Sutherland’s formula, is a real time approximation for how the viscosity of gases depends on the temperature. This formula or the law is based on an idealized intermolecular-force potential and reads where Sμ is an effective temperature called the Sutherland constant. Each gas has its own Sutherland constant. Equationis strictly valid only for single-component gases at low pressure. It does, however, work well for air because air is mainly composed of nitrogen and oxygen, which have very similar properties. Parameter values for some common gases