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R-1243zf is a new refrigerant that could replace R-134a. Its thermodynamic properties represented in the equation of state (EOS) play an essential role in analyzing and designing thermal systems. The EOS exists without including caloric property data due to unavailable data during the development time. New EOS was developed explicitly in Helmholtz free energy and optimized to represent the experimental data accurately and maintain thermodynamic consistency. The optimization process undergoes using a genetic algorithm and weighted-least squares regression. The experimental data used in the optimization have a range of 233-430 K and 0.106-34.6 MPa and were validated from the extrapolation and consistency to confirm the reliability. The average absolute deviation from the data is 0.48% for the ideal gas isobaric specific heat, 1.7% for the isochoric specific heat, 0.33% for the speed of sound, 0.22% for the liquid density in single-phase, 0.49% for the vapor density in single-phase, 0.96% for the vapor pressure, 2.2% for the saturated liquid density, and 3.2% for the saturated vapor density. The EOS has a reasonable extrapolation behavior from the triple point up to 700 K and 100 MPa. [ABSTRACT FROM AUTHOR]

The article presents the research on the topic of system limit was first proposed by Tek in 1959 and the work extended the approach by Souders and Brown by incorporating concepts of drop stability developed by Hinze. Topics include the work by Hinze showed that there was a definite correlation between the maximum stable droplet size of liquid droplets entrained in vapor, and the Weber number relates the drag force on droplet in a vapor stream to the cohesive force that hold a droplet together.

Production from shale reservoirs is receiving more attention from the petroleum industry. However, there are many complexities associated with optimal production of shale reservoirs. One complexity is the unclear fluid-phase behavior in shale nanopores. In the shale nanopores, the interaction between the pore wall and fluid molecules can significantly change the fluid-phase behavior from the bulk (unconfined) condition. Therefore, the type of pore material can influence the fluid-phase behavior. There have been several recent efforts to model the confined fluid-phase behavior in shale reservoirs. However, the effect of pore material on fluid-phase behavior in shale reservoirs has not been addressed in the previous studies. In this paper, to have a better understanding of phase diagrams in different shale environments, we perform molecular simulations with three materials (two inorganic minerals and one kerogen) and two types of nanopores (slit and cylinder) to model the confined-phase behavior of pure fluids (methane and propane) and one ternary fluid (C1/C3/nC5). From the pure-fluid simulations in the pores of three diameters (4, 7, and 10 nm), confined liquid densities are decreased, whereas vapor densities are increased in the slit and cylinder pores. When pore diameters are increased, critical points are shifted to low densities and high temperatures. Critical temperature and density under confinement can deviate as high as 15 and 60%, respectively, from the original values in bulk. Molecular simulations are conducted for the ternary fluid in the slit and cylinder pores at 160°F. Under confinement, there is a large shift in the nC5 composition of the vapor phase in the ternary diagrams, whereas only small changes have been observed in the ternary diagrams of liquid phase. The density difference between two phases is reduced. Additional tests are performed at one typical shale temperature (290°F) for this ternary fluid in both nanopore types. Phase separation is observed in the slitpore tests, although only one phase is formed in the tests of the cylinder pores. Because the cylinder pore has more adsorption surface area compared with the slit pore, a stronger adsorption effect is introduced in all tests of the cylinder pores. Based on the comparison of all results (pure fluids and ternary fluid) from the three materials, the calcite pores provide a stronger confinement effect on fluids, and the other two materials have a similar confinement effect on the phase diagrams. [ABSTRACT FROM AUTHOR]

The aim of this work is to model the surface tension for (CH 4 + H 2 O), (N 2 + H 2 O) and (CH 4 + N2) + H 2 O systems. The linear gradient theory (LGT) in combination with the cubic-plus-association equation of state (CPA EOS) has been applied for modeling the surface tension of (CH 4 + H 2 O), (N 2 + H 2 O) and (CH 4 + N 2 ) + H 2 O systems. The influence parameter in terms of the liquid and vapor densities has been applied. The geometric mixing rule has been also used for the influence parameter of the mixtures. First, the influence parameters of pure components have been determined. Then, the binary interaction coefficients for the influence parameters of (CH 4 + H 2 O) and (N 2 + H 2 O) systems have been correlated. The influence parameters of pure components and binary interaction coefficients have been applied for (CH 4 + N 2 ) + H 2 O system. The calculated surface tension values have a good agreement with experimental data for (CH 4 + N 2 ) + H 2 O system (overall AAD ∼ 3.42). [ABSTRACT FROM AUTHOR]

Cavitation around a hydrofoil has significant three-dimensional features. The full cavitation model and a RNG k-ε, turbulence model with a modified turbulence viscosity coefficient and which related to the vapor and liquid densities in the cavitating region were use to simulate cavitation around a hydrofoil, with emphasizing on cavity's three-dimensional features. Computations were made on the three-dimensional flow field around a NACA66 hydrofoil at a 6 deg angle of attack. The results show that the shedding frequency on the 3D hydrofoil agrees well with the experimental data. The computed results also capture main feature of the 3D cavitation, which had a crescent shaped cavity because of the spa wise velocity. This span wise velocity is due to the span wise pressure gradient caused by the lateral vortex near the side wall of the tunnel. [ABSTRACT FROM AUTHOR]