Article
Thermophysical Properties of Materials
2020. V. 58. № 3. P. 333–341
Vorob'ev V.S., Ustyuzhanin E.E., Ochkov V.F., Shishakov V.V., Tun AungTuRa, Rykov V.A., Rykov S.V.
Study of the phase boundary for C6F6 and SF6 under microgravity
Annotation
Two groups of experimental data obtained in the vicinity of the critical point are discussed. Group I describes the level ht of the meniscus separating the two phases of the substance in the cell. The measurements were performed for SF6 under conditions (g=9.8 m s^{–2}) during an experiment conducted in a space laboratory. Group \rm II includes data on the density of liquid and vapor measured for \rm C_6\rm F_6 along the saturation curve under conditions (g = 9.8 m s^{–2}). In both cases, the studied two-phase sample is located in a horizontal cylindrical cell. In the second experiment, the gravitational effect was also measured along the isotherms as the dependence of the sample density on the height h measured from the bottom of the cell. An equation relating the ht level (experiment \rm I) with such functions as the order parameter f_s and the average diameter f_d is derived in this work. The obtained equation describes the initial experimental data at relative temperatures \tau = (T - T_c)/T_c = 2 \times 10^{–6}–0.01. An approach is considered that takes into account the influence under microgravity (g = g_M \ll 9.8 m s^{–2}) on the height h (experiment \rm II). The dependences that represent f_s and f_d and the density of the liquid and gas phases along the saturation curve of these substances are obtained. These dependences agree satisfactorily with the results of experiments \rm I and \rm II in a wide temperature range and correspond to the scaling theory of critical phenomena.
Article reference:
Vorob'ev V.S., Ustyuzhanin E.E., Ochkov V.F., Shishakov V.V., Tun AungTuRa, Rykov V.A., Rykov S.V. Study of the phase boundary for \rm C_6\rm F_6 and \rm SF_6 under microgravity, High Temp., 2020. V. 58. № 3. P. 333
Vorob'ev V.S., Ustyuzhanin E.E., Ochkov V.F., Shishakov V.V., Tun AungTuRa, Rykov V.A., Rykov S.V. Study of the phase boundary for \rm C_6\rm F_6 and \rm SF_6 under microgravity, High Temp., 2020. V. 58. № 3. P. 333