Comparison between Experimental and Theoretical Estimations of the Thermal Expansion, Concentration Expansion Coefficients, and Viscosity for Binary Mixtures under Pressures up to 20 MPa

Abstract

In this work, we have measured the densities of binary mixtures of n-dodecane, 1-phenyl-2-methylpropane, and 1,2,3,4-tetrahydronaphthalene for pressures varying from (0.1 to 20) MPa at an average temperature of 25 °C. By a derivative method, we have determined the thermal expansion and concentration expansion coefficients for binary mixtures of equal mass fraction. In addition, viscosities have been measured and compared with theoretical estimates. To accurately predict the thermal expansion and concentration expansion coefficients, the densities of the binary mixtures were calculated using PC-SAFT, Peng-Robinson, and volume translated Peng-Robinson equations of state. The comparison with measured densities showed that PC-SAFT has a better agreement with experimental data than the other equations of state. From calculated densities we evaluated the thermal expansion and concentration expansion variation coefficients. We have found that PC-SAFT gives a suitable prediction for the two derivative properties unlike the two other equations of state. The combination of the model of Lohrenz-Bray-Clark for the viscosity of liquid mixtures and the densities calculated with the three equations of state gave a poor prediction of the viscosities of the binary mixtures. Experimental SectionMaterials. The 1,2,3,4-tetrahydronaphthalene (99 %), ndodecane (99+ %), and 1-phenyl-2-methylpropane (99 %) were † Part of the special section "2008 European Conference on Thermophysical Properties".

Gas depletion through single gas bubble diffusive growth and its effect on subsequent bubbles

“…Any possibly present residual inertial fluid motion near the substrate will damp out due to the presence of the chip. The time in which this happens is set by the speed at which the chip momentum boundary layer grows (approximately δ m ∼ √ νt ∼ R det ), such that this time can be estimated as t ∼ R 2 det /ν, where ν = 9.58 × 10 −7 m 2 s −1 is the kinematic viscosity of water (Frank et al 1996;Bataller et al 2009). This time is calculated to be of the order of tenths of a second.…”

“…For our specific case, λ c has a value of 6.5 × 10 −4 m 3 kg −1 . Often, λ c is approximated by λ c = (M g /ρ l ) − V g (Bataller et al 2009), where M g is the molecular mass of the gas, ρ l is the liquid density and V g is the partial volume of the gas in the mixture. However, this partial volume cannot be measured with the desired precision by the means we have access to; therefore, we have used the original definition as in (3.5).…”

Concentration dependent refractive index of a binary mixture at high pressure

“…In order to perform these comparisons one needs to know the values of the molecular polarizability of the two molecules as well as the density and the mass expansion coefficient of the mixture as a function of the pressure. While the latter have been measured by some of us in a previous experiment, 35 the former is not easy to measure and there exist no reference value in literature for the two components of choice at high pressure.…”

“…The density and mass expansion coefficient of the THN + C12 mixture were previously measured 35 in the pressure range from atmospheric pressure up to 20 MPa. For this reason the comparison between experimental data and theoretical predictions will be performed only up to this pressure level.…”

Thermodynamic modeling and experimental speeds of sound, densities, and refractive indexes of (tetralin+n-dodecane)

“…Following the works of Yu and Tsai [10] and our recent works on tetralin mixtures [5,6], (tetralin + n-dodecane) is expected to presented V E close to zero. Also, we had derived isothermal compressibility, k T , from our data and compared it to the values obtained from high pressure density measurements for pure tetralin [11], pure dodecane [12], and a mixture of tetralin and dodecane [13].…”