Thermodynamic properties for the triangular-well fluid

Equation of state of a long-range triangular-well fluid

“…The critical constants obtained from the MFA-TW EOS at various l are listed in Table 1 together with the literature values [23]. As can be seen from Table 1, the critical point values obtained from MFA-TW EOS are more consistent with the results of MC simulation for smaller l values, but, as l increases, the results obtained from the two equations approach each other.…”

“…The densities of the coexisting phases and the saturated vapour pressure are obtained by the simultaneous solution of Equations (17) and (18). A comparison of the different theoretical approaches and computer simulation is presented for the fluid-fluid coexistence curves of the long-range triangular-well fluid in Figure 3 for different potential range parameters l. Figure 3 clearly shows that the MFA-TW EOS reproduces the simulated coexistence [23]. Dotted lines are reproduced from Ref.…”

“…Wang and Lai [22] presented the phase diagram for a short-range attractive TW potential within the context of a van der Waals-like theory. Betancourt-Cardenas et al [23] also reported another molecular simulation calculation for this potential. First, they reported the thermodynamic properties and vapour-liquid phase diagrams for a TW fluid with a well of up to twice the HS diameter ð1:2 l 2Þ by means of an analytic EOS based on second-order BH perturbation theory and molecular simulation.…”

“…We have calculated the main thermodynamic quantities such as the excess internal energy U Ã ¼ U ex =Nk B T and the reduced pressure P Ã ¼ P 3 =" as a function of density at different temperatures and compared the results with the results of Largo and Solana based on second-order perturbation theory [20], the LR-TW EOS due to Betancourt-Cardenas et al, which is based on first-order perturbation theory, and the MCNVT simulation data taken from the literature [23]. Figure 1 shows the reduced pressure as a function of the density at different reduced temperatures for selected values of l. In general, the agreement for the pressures obtained from the MFA-TW EOS, the computer simulation and the LR-TW EOS is good for all values of l. In the case of l ¼ 2, however, it can be seen that, for low temperatures and high densities, the LR-TW EOS and the Largo and Solana EOS are slightly better than the MFA-TW EOS, but, for low and intermediate densities, there is almost no difference between the results at all temperatures.…”

“…The simulation data are taken from the literature: Open symbols represent the data from Ref. [23] and filled symbols from Ref. [5].…”