Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- The speed of sound and isentropic compressibility of liquid difluoromethane (HFC32) fromT=(248 to 343) K and pressures up to 65 MPaPublication . Pires, P. F.; Guedes, H. J. R.This work reports experimental data on the speed of sound in liquid difluoromethane ŽHFC32, or R32. from T s Ž248 to 343. K and pressures up to 65 MPa. The results were obtained using a newly-built apparatus, calibrated with toluene over the whole experimental region, and show good agreement with two available data sets. The uncertainties are "0.01 K in the temperature, "0.025 MPa in the pressure up to 35 MPa, and "0.2 MPa above this value. The final uncertainty on the speed of sound is estimated to be "0.2 per cent. The data were fitted using a simple analytical equation and the results are discussed. The isentropic compressibility was calculated over the Ž p, T. surface where the reported speed of sound values and the corresponding literature densities overlap.
- The speed of sound, and derived thermodynamic properties of liquid trifluoromethane (HFC23) fromT=(258 to 303)K at pressures up to 65MPaPublication . Pires, P. F.; Guedes, H. J. R.This work reports experimental data of the speed of sound in liquid trifluoromethane (HFC23, or R23) from T = (258 to 303) K at pressures up to 65 MPa, measured with a pulse-echo method adapted from Papadakis(1) and Guedes et al.(2) The results are fitted to a rational approximant and compared with literature data.(3) Derived thermodynamic properties such as the isentropic compressibility κs, the isothermal compressibility κT , the cubic expansion coefficient αp, and the specific heat capacity at constant pressure cp are calculated by combining the present experimental data with the density values published by other authors.(4–11) The estimated properties are compared, where possible, with literature data.