Study of thermophysical properties of real gases by different potential models
R. Khordad, A. Ghanbari and S. F. Taghizadeh
The influence of attractive term of interaction potential on heat capacities (𝐶𝑝, 𝐶𝑣) and sound speed of real gases Ar, Kr and Xe is investigated. Two different potential models were introduced and the second virial coefficient of the potentials was analytically determined. The introduced potentials include different attractive terms. By using the two potential models, we have determined heat capacities at constant pressure and volume and speed of sound of aforementioned gases. Our obtained data have been compared with available results. The obtained data show that the potential attractive term has a key role in determining the thermodynamic functions of the gases. It is revealed that the obtained heat capacities by using both potentials are in good agreement with experimental data. But, the obtained results by potential model (1) have more agreements with experimental data. The speed of sound of Ar determined by model (1) at high pressure and temperatures are in good agreement with available data. The sound speed of Kr computed by the model (2) at high temperatures and low pressure has good agreement with experimental data. Finally, sound velocity of Xe determined by the model (2) at high temperatures and pressures gives more agreement in comparison with available data.
Keywords: Heat capacity, Speed of sound, Potential model