Thermodynamic properties of air from 60 to 2000 K at pressures up to 2000 MPA

A thermodynamic property formulation for standard dry air based upon experimental P-p-T, heat capacity, and speed of sound data and predicted values, which extends the range of prior formulations to higher pressures and temperatures, is presented. This formulation is valid for temperatures from the solidification temperature at the bubble point curve (59.75 K) to 2000 K at pressures up to 2000 MPa. In the absence of experimental air data above 873 K and 70 MPa, air properties were predicted from nitrogen data. These values were included in the fit to extend the range of the fundamental equation. Experimental shock tube measurements ensure reasonable extrapolated properties up to temperatures and pressures of 5000 K and 28 GPa. In the range from the solidification point to 873 K at pressures to 70 MPa, the estimated uncertainty of density values calculated with the fundamental equation for the vapor is plus or minus 0.1%. The uncertainty in calculated liquid densities is plus or minus 0.2%. The estimated uncertainty of calculated heat capacities is plus or minus 1% and that for calculated speed of sound values is plus or minus 0.2%. At temperatures above 873 K and 70 MPa, the estimated uncertainty of calculated density values is plus or minus 0.5%, increasing to plus or minus 1% at 2000 K and 2000 MPa.