MEASUREMENTS OF THE VISCOSITY OF R11, R12, R141B, AND R152A IN THE TEMPERATURE-RANGE 270-340-K AT PRESSURES UP TO 20-MPA

This paper reports new measurements of the liquid viscosity of R11, R12, R141b, and R152a in the temperature range 270 to 340 K and pressures up to 20 MPa. The measurements have been carried out in a vibrating-wire instrument calibrated with respect to the standard reference value of the viscosity of water. It is estimated that the uncertainty of the present viscosity data is one of 0.5%. The experimental data have been represented by polynomial functions of temperature and pressure for the purposes of interpolation. A recently developed semiempirical scheme, based on considerations of hard-sphere theory, is employed to correlate successfully the viscosity and the thermal conductivity of these refrigerants as a function of their density.