High temperature–high pressure thermal conductivity of argon

Abstract

A conductivity column‐type apparatus was built and tested for measuring the thermal conductivities of gases at high temperatures and at high pressures. Two columns of different lengths were used in order to minimize end effects. The temperature and pressure limits were established below which multicellular convection cells did not form inside the column. The thermal conductivities of argon were measured in the temperature range 400 to 750 K and in the pressure range 0.1 to 8 MPa. The data were correlated by the expression where a=0.2678×10−3, b=0.7401, A=0.2839×10−4, B =0.1650×10−4, C=−0.1065×10−6, p0=0.1 MPa, and λ is in W m−1 K−1, T in K, and P in MPa. The thermal conductivity values obtained were compared with (1) existing data, (2) with results of viscosity measurements by means of the Eucken factor, and (3) with theoretical predictions based on a model for nonattracting rigid spherical molecules.