No abstract

The mass diffusion coefficients of dimethyl carbonate in heptane and in air were measured at T = (278.15 to 338.15) K under atmospheric pressure. The experiments were carried out using a digital holographic interferometry system that was constructed by our group. The mass diffusion coefficient of KCl in standard aqueous solution at a temperature of 298.15 K and condensation of 0.33 mol·L−1 was measured to verify the accuracy and reliability of the system. The experimental uncertainties in temperature and mass diffusion coefficient are estimated to be no greater than ± 0.16 K and ± 0.2 %, respectively.

In this article, a method which can be used to measure the viscosity of liquids with an inclined tube at high pressures and for low-boiling substances is described. The measurement equation was established. The measuring methods for two unknown parameters which are in the measurement equation are presented, and a viscosity measurement system was designed and constructed, which consists of an experimental cell, an inclination-angle control subsystem, a constant temperature subsystem, and a data collection and process subsystem. At atmospheric pressure, the kinematic viscosity of pure water was measured at temperatures from 273.15 K to 333.15 K to demonstrate the performance of the apparatus. The results show that the absolute average relative deviation is 0.84% in comparison with reliable literature values. The kinematic viscosity of saturated liquid R134a and R600a were also measured at temperatures from 273.15 K to 295.15 K and 273.15 K to 300.15 K, respectively, and the corresponding absolute average relative deviations are 1.04% and 1.02% in comparison with reliable literature values. These experimental results demonstrate the performance of the apparatus, while providing estimates of the uncertainty and reliability of the experimental system.

No abstract

On the basis of the Mach−Zehnder optical interference model, a digital holographic interferometric experimental system was set up, and a new diffusion cell especially for measuring the binary gas diffusion coefficient was designed and constructed. With the theory for measuring the binary gas diffusion coefficient and the interference fringe processing method introduced before, the binary gas diffusion coefficient can be obtained. In comparison with the reference data of O2 in air, the experiment accuracy of the system was verified. The diffusion coefficients of H2, He, NH3, CH4, O2, and CO2 in air at T = (278.15 to 343.15) K under normal atmospheric pressure were measured and compared with results of a correlation. The comparison showed that the results are reasonable.

No abstract

Laser holographic interferometry is the newest method to measure the mass diffusion coefficient and has been widely used in recent years. The processing of interference fringe images is a critical step of getting the final precise experimental results. On the basis of Fourier transformation and phase measurements, a new method of processing Mach-Zehnder interference fringes is introduced in this article. By experimental verification and uncertainty analysis, the accuracy of this method is validated. Mass diffusion coefficients of ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, two new fuel additives in air were measured with the method introduced in this study.

No abstract