In this study, strut support effects on a slanted cylinder afterbody were investigated by a magnetic suspension and balance system installed in a wind tunnel. The results showed that the aerodynamic ...characteristics with respect to the critical Reynolds number where the flow field and aerodynamic forces change significantly. In the cases with the dummy strut, the range of the critical Reynolds number decreases, and the variation depends on the location of the strut. The size of the recirculation region and the separation bubble on the wake center plane also changes depending on the location of the strut. Moreover, additional weak vortices are observed to be formed behind the strut, which changes the wake structure. That change affects the variation of the vortex core wandering, and is a factor in the power spectral density peaks observed in previous studies. It is suggested that the strut support strongly interferes with the flow around the test model and should be carefully considered.
•A wind tunnel test model was supported by magnetic force without mechanical support.•A critical Reynolds number in the cases with strut support is low compared with that in the cases without support.•The recirculation region and the separation bubble shrink in the cases with strut support.•Additional vortices appear behind a strut support.•No spectral peaks of fluctuations in the vortex core position are observed in the case without support.
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•GERG2008 EoS was embedded in volumetric-gravimetric technique to measure multicomponent total, partial/individual components uptakes into the mixture.•Pure CO2 and CH4 adsorptions ...were considerably dropped with presence of 1% H2O in binary gas–vapor premixed mixtures.•The total and partial uptakes of the 50:50, 70:30, 30:70 of CO2:CH4 binary gaseous mixtures were decreased subsequently compared to the ternary mixtures of CO2:CH4:H2O.•The predicted and simulated ternary mixtures by ANN model were deliberated decent agreement and consistency with the experimental data.
In this work GERG2008 EoS was incorporated in a volumetric-gravimetric-chromatographic technique. The system utilized to measure in-mixtures components experimental selective isotherms individually, with the ability to analyze water vapor–gas components in the same mixture. 5A zeolite was used as a solid adsorbent for binary and ternary CO2/CH4/H2O mixtures adsorption at 50°C and 70°C temperature up to 10bar pressure. Artificial neural network (ANN) modeling was applied to predict ternary and binary gaseous with the presence of water mixtures. This study delivered better clarification in the field of selectivity and reliability in the term of multicomponent and dual phase mixtures analysis.
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•Densities of CO2/N2/O2 were measured at 300.15–353.15 K and 5–18 MPa.•Uncertainties of temperature and pressure were 0.01 K and 0.005 MPa.•The density measurement uncertainty was ...estimated at 0.138 kg·m−3.•The presence of N2 and O2 decreased the density of pure CO2.•Discrepancy between our data and GERG-2008 became larger when near critical point.
As a thermodynamic property, the density of CO2 mixtures plays an important role on carbon capture and storage. The densities of two CO2/N2/O2 ternary mixtures were measured at temperatures from (300.15–353.15) K and pressures from (5–18) MPa using a high-precision magnetic suspension balance. The temperature and pressure uncertainties were 0.01 K and 0.005 MPa, respectively. The density measurement uncertainty was estimated as 0.138 kg·m−3. Impurities decreased the density of pure CO2 and the more the impurities were, the larger the reduction was. The densities of mixtures were calculated using GERG-2008 EOS and compared with experimental data. When the temperature and pressure were far away from the critical region, the discrepancy between the experimental data and GERG-2008 EOS calculations was small.
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•CO2 solubility in mixed ionic liquids (m-ILs) that have different functionalities.•CO2 solubility measured in m-ILs at 353–393K and at pressures up to 15 MPa.•Synergistic behavior ...observed in CO2 Henry’s constants with m-IL composition.•Prediction of CO2–m-ILs solubility with equations of state from binary data.
In this work, mixtures of 1-butyl-3-methylimidazolium chloride (bmimCl) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (bmimTf2N) were chosen to study because bmimCl is suitable for processing biomass and bmimTf2N is suitable for increasing carbon dioxide (CO2) solubility in the ionic liquid phase. Solubilities of CO2 in mixed ionic liquid systems (bmimCl and bmimTf2N) were measured at (353–393) K and at pressures up to 15MPa with a magnetic suspension balance technique. Mixed ionic liquids were prepared at mole ratios, bmimCl: bmimTf2N of 0.75: 0.25, 0.50: 0.50 and 0.25: 0.75. CO2 solubility in mixed ionic liquids changed regularly from that in single bmimCl to that in single bmimTf2N. By assuming mixed ionic liquids as a mixture of two ionic liquids, the ε*-modified Sanchez-Lacombe equation of state could predict CO2 solubility data with pure component parameters of single ionic liquids and interaction parameters for bmimCl-CO2, bmimTf2N-CO2 and bmimCl-bmimTf2N to within an average relative deviation of 2.4%.
This paper reviews the 40-year evolution and application of the magnetic suspension balance (MSB) and discusses some challenging issues of the technique. An MSB, as defined herein, is a magnetic ...suspension coupling (MSC) connected to an analytical balance. With an MSC, an object can be weighed in a different environment than the balance itself, making it possible for contactless weighing. Over the past 40 years, the MSB has been commonly used in research areas requiring accurate object weighings, notably gas density measurements by MSB-based densimeters and gas adsorption measurements by MSB-based sorption analyzers. More than 15 MSB-based densimeters have been built to date; these are generally called two-sinker densimeter and single-sinker densimeter. They have produced highly accurate density data of many pure fluids and fluid mixtures. These data serve as the basis for the development of reference equations of state, which play an essential role in various industrial and scientific areas. Moreover, such systems are central to the metrology program of many countries. The MSB technique is also very successful in adsorption science: more than 85 MSB-based sorption analyzers have been set up in over 20 countries. The number of new MSB-based sorption analyzers, and peer-reviewed publications resulting from them, are both increasing exponentially since 2004. They have produced highly reliable gas adsorption data at high pressures for many applications, mainly in the energy and environmental sectors. Although further development of innovative instruments based on the MSB is threatened by the proprietary nature of MSB technology, the development will continue, e.g., toward cryogenic measurements and a more compact design.
We have investigated the CO2 absorption properties in 1-ethyl-3-methylimidazolium (Emim) ionic liquids with the anions (TFSA, bis(trifluoromethanesulfonyl)amide; BETA, ...bis(pentafluoroethanesulfonyl)amide; NFBS, nonafluorobutanesulfonate; BF4, tetrafluoroborate) using a magnetic suspension balance at 313.15 K and pressures up to 6 MPa. To obtain accurate CO2 solubility, the buoyancy correction was made by taking account of the volume expansion of ionic liquids caused by CO2 dissolution. In the present work, Sanchez–Lacombe equation of state was used for such volume corrections at high pressures. As a result, the solubilities of carbon dioxide in EmimTFSA are consistent with the literature data. The solubilities of carbon dioxide in the ionic liquids studied showed typical pressure dependence as physical absorption, and increased in the following order of the anion: BF4 < NFBS < TFSA < BETA.
This article presents an experimental device specially designed for the continuous measurement of mass and dimensions of samples submitted to convective drying. This experimental device consists of a ...magnetic suspension balance and an image acquisition system. The sample deformation is determined by image correlation using a custom software. The entire system is able to achieve accurate mass and dimension measurements over a wide range of temperature and relative humidity. To present the potential of this equipment, experimental data of highly deformable food products (potato and apple) submitted to several drying conditions are presented. The obtained results confirm that it is required to consider the actual sample surface to determine the mass flux. This allowed a first drying stage to be observed for potato. Clear differences in physical behavior of these two vegetable products were also observed, for example, an isotropic shrinkage behavior for potato and an anisotropic behavior for apple. These results were explained by the anatomical structure of the products.
•Accurate densities of CO2–CH4 were measured at 300–308.15K and 2–18MPa by MSB.•Combined standard uncertainty of T, p, and uM(ρ) are 0.02K, 0.001MPa and 0.029kg·m−3.•The measured density agrees well ...with GERG-2008 as x<0.60 with deviation within 2.0%.•The max deviation with GERG-2008 appears as T–p close to critical point at high x.
The accurate densities of CO2–CH4 binary mixtures with CO2 mole fraction of 0.0998, 0.2017, 0.3997, 0.6015, 0.7985 and 0.8988 at temperatures from (300 to 308.15)K and pressures from (2 to 18)MPa were measured using a high-precision magnetic suspension balance. The combined standard uncertainties of temperature and pressure were estimated as 0.02K and 0.001MPa, respectively. The density measurement uncertainty of MSB was estimated as 0.029kg·m−3. Taking the effect of composition uncertainty and sorption into account, the combined standard uncertainties in the density measurement of CO2–CH4 mixtures were around 0.30% with CO2 mole fraction lower than 0.60 while they increased up to 0.96% with CO2 mole fraction higher than 0.80 at pressure of 9.0–11.0MPa. The measured densities were compared with the calculation from GERG-2008 EOS. It showed relatively good agreements between the GERG-2008 EOS and the measured densities with CO2 mole fraction lower than 0.60 at 300K as the relative deviations were generally within 2.0%. When CO2 mole fraction was higher than 0.80 at 300K, the relative deviations firstly increased to the maximum 3.73% in the vicinity of critical pressure and then decreased close to zero with the increasing pressure. The experimental data at other temperatures have the similar variation trends. Thus it’s difficult to apply GERG-2008 EOS to predict the density characteristics of CO2–CH4 binary mixtures with high CO2 mole fraction in the vicinity of the critical point accurately.
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► The solubility of CO2, CH4 and C2H6 in emimEtSO4 is measured with a magnetic suspension balance. ► New data and literature results have been modeled with a Group Contribution ...equation of state. ► A specific group definition is required to model data of ionic liquids with a MeSO4 anion. ► Deviations between model and experiments are lower than 10% in most cases. ► Deviations of 34% are observed in the case of the solubility of ethane in the ionic liquid.
The solubility of different gases (carbon dioxide, methane, ethane, carbon monoxide and hydrogen) in ionic liquids with an alkyl sulfate anion has been modeled with the Group Contribution equation of state developed by Skjold-Jørgensen. New gas solubility measurements have been carried out with a high pressure magnetic suspension balance in order to cover pressure and temperature ranges not considered in previous studies and to obtain more experimental information for the correlation of parameters of the equation of state. New solubility measurements include the solubility of carbon dioxide in 1-ethyl 3-methyl imidazolium ethyl sulfate emimEtSO4 at temperatures of 298K and 348K and pressures ranging from 0.3MPa to 6.5MPa, the solubility of methane in emimEtSO4 at a temperature of 293K and pressures ranging from 0.2MPa to 10.2MPa, and the solubility of ethane in emimEtSO4 at temperatures of 323K and 350K and pressures ranging from 0.2MPa to 4MPa. Results show that the Group Contribution equation of state can be used to describe the solubility of gases in alkyl sulfate ionic liquids as well as infinite dilution coefficients of alkanes in the ionic liquids, with average deviations between experiments and calculations ranging from 1% to 10% in the case of mixtures with CO2, CO, CH4 and H2 with the alkyl sulfate ionic liquids to up to 34% in the case of the solubility of ethane in emimEtSO4.
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