I have trouble finding physical properties (for the file props.dbs) of radicals (O,H,OH) which I need to model in order to be able to get good predictions of NOx emissions. Has anybody experience with this and/or can suggest some good source for these properties?

The properties are namely density, Cp, molecular viscosity, thermal conductivity, heat and temperature of formation. Btw, the heats of formation of hydrocarbons included in the database surprisingly don't correspond with commonly available data. What's your suggestion?

Thanks, Jirka.

Try looking on the NIST website. You can get most of the data you need.

Thanks, but I tried this one as well as CEA/NASA site, and the data published there is not complete.

Maybe if there's someone with personal experience of NOx modelling in Star..?

The properties of NOx you asked about have practically no influence on the fluid properties, since their concentrations in the fluid are very small. These properties are not used by STAR-CD since you define the scalars for these species as passive.

Yes, thank you, Daniel, but my question applies to the situation when you use PPDF modelling, not local source. For the first approach you need the properties for proper calculation of NOx levels even though they are certainly not important for the flow solution.

density - equation of state (ideal gas law) Cp, enthalpy, heat of formation - NIST WEBBOOK Viscosity, conductivity , binary diffusion coefficient - gas kinetic theory (statistical mech)