Viscosity Deviations Research Articles

Densities, viscosities, and refractive indices of binary mixtures of tri-n-butyl phosphate with propan-2-ol and butan-2-ol at 303.15, 308.15, 313.15, 318.15, and 323.15 K

Densities, viscosities, and refractive indices of binary liquid mixtures of tri-n-butyl phosphate (TBP) with propan-2-ol and butan-2-ol at different temperatures between 303.15 and 323.15 K at an interval of 5 K and across the entire range of composition were measured. The data were used to calculate derived properties, such as excess molar volumes, excess thermal expansivities, deviations in viscosities, excess free energies of activation for viscous flow, and deviations in refractive index. The variation patterns of these properties concerning composition and temperature for the propan-2-ol + and butan-2-ol + TBP systems were discussed and attributed to probable intermolecular hydrogen bonding and geometric effects. Notably, the influence of hydrogen bonding was substantial, as evidenced by trends in excess molar volumes and deviations in viscosities. Concentration-dependent polynomial equations were used to fit the measured data of density, viscosity, and refractive index, while Redlich-Kister-type equations were applied for the excess properties. The densities and viscosities were correlated using the Jouyban-Acree model. The correlating abilities of various models, such as Grunberg-Nissan, Tamura-Kurata, Heric, Ausländer, McAllister-3, and McAllister-4 body models, were also evaluated using the viscosity data. Additionally, six new pairs of UNIFAC-VISCO group interaction parameters were computed to predict viscosities of TBP in systems involving alkanes, aromatics, and alcohols, extending the application range of the group contribution model.

Physiochemical properties of the binary liquid mixtures of 2-methyl-2,4-pentanediol with selected di- and tri-chloro-substituted benzene and correlation with the Jouyban–Acree model at various temperatures

ABSTRACT Excess molar volume, excess isentropic compressibility, deviation in viscosity and excess Gibbs free energy for the activation of viscous flow for binary mixtures of 2-methyl-2,4-pentanediol (MPD) with 1,2-dichlorobenzene (1,2-DCB), 1,3-dichlorobenzene (1,3-DCB) and 1,2,4-trichlorobenzene (1,2,4-TCB) components selected compositions are determined from the measured values of densities (ρ), speeds of sound (u) and viscosities (η) of pure components and their mixtures from 303.15 K to 313.15 K. The results are analysed in terms of intermolecular interactions or hydrogen bonding or hetero-association interactions in the binary mixtures. The Prigogine–Flory–Patterson (PFP) theory is applied to identify the predominant molecular interaction. The results of Jouyban–Acree model are discussed in terms of mean relative deviation (MRD) and individual relative deviation (IRD) between the calculated and experimental densities, speeds of sound and viscosities as accuracy criteria.

Viscosity, Interfacial Tension, and Density of 2-Propanol and Acetone up to 423 K by Surface Light Scattering and Conventional Methods

Despite the extensive use of 2-propanol and acetone in a wide range of applications in the chemical industry and in energy engineering, there is a lack of experimental data in the literature for their thermophysical properties including viscosity, interfacial tension, and density, especially at elevated temperatures beyond the respective normal boiling points. In the present study, the liquid viscosity and interfacial tension were determined simultaneously by surface light scattering (SLS) with average expanded uncertainties of (1.7 and 0.9)% at or close to saturation conditions for temperatures between (273 and 403) K. Furthermore, capillary viscometry (CV) and vibrating-tube densimetry were employed to measure the liquid viscosity at ambient pressure of 0.1 MPa from (283 to 353) K and the liquid density close to saturation conditions between (278 and 423) K. The obtained density data were used for the evaluation of both SLS and CV experiments. In comparison with literature data, the present density data show agreement for 2-propanol over the entire temperature range. In contrast, deviations of up to 0.5% at the maximum temperature can be found for acetone. For the viscosity and interfacial tension at low temperatures, agreement of the measurement results among each other and with literature data is mostly found. At elevated temperatures, the increasing deviations of the present experimental viscosity and interfacial tension data from recommended correlations indicate a lack of reliable data needed for their development. Overall, this work contributes to an improvement of the database for viscosity, interfacial tension, and density of 2-propanol and acetone over a wide temperature range up to 423 K.

An RBF-based artificial neural network for prediction of dynamic viscosity of MgO/SAE 5W30 oil hybrid nano-lubricant to obtain the best performance of energy systems

Technological progress and complications in microfluidics usage have led researchers to use nanomaterials in different scientific fields. The properties and characteristics of hybrid Nanofluids are more enhanced compared to nanofluids based on single nanoparticles and conventional liquid. Recently, modeling methods have replaced most common statistical methods. Due to the high accuracy of the response and generalizability in various conditions, artificial neural networks (ANNs) to estimate nanofluids’ viscosity and thermal conductivity have become common. Dynamic viscosity (μ) (estimation analyzes one of the key factors in determining the hydrodynamic behavior of nanofluids. In this manuscript, an RBF-ANN is used to simulate the input-output relation of dynamic viscosity of the MgO- SAE 5W30 Oil hybrid nanofluid versus three important parameters, including volume fraction of nanoparticles, temperature, and shear rate. The results show that for this nanofluid, by increasing temperature and shear rate, the dynamic viscosity is decreased. In contrast, the volume fraction of nanoparticles directly affects the output, although this consequence can be neglected. By increasing the temperature from 5° to 55°C, the dynamic viscosity would decrease. Also, changing the shear rate from 50 to 1000 rpm decreases the dynamic viscosity from 400 cP to 25 cP. It is worth mentioning that the obtained trends and deviation of dynamic viscosity for MgO-SAE 5W30 Oil hybrid nanofluid versus temperature, the volume fraction of nanoparticles, and shear rate can be used by the academic community as well as an industrial section to obtain the best performance of energy systems based on this nanofluid.

Molecular interactions between 2-methyltetrahydrofuran and alcohols: A combination of thermodynamic, spectroscopic and quantum chemistry studies

New data of density (ρ), viscosity (η), and speed of sound (u) have been determined at T = (288.15–303.15 K) and p = 93.2 kPa for the binary mixture of {2-methyltetrahydrofuran + ethanol, or + 1-propanol, or + 1-butanol, or + 1-pentanol} over the entire composition range. These results were used to calculate the excess molar volume (VmE), isentropic compressibility deviation (Δκs), viscosity deviation (Δη), and Gibbs excess activation energy (ΔG*E), which were correlated by a Redlich-Kister polynomial. For all systems studied, the values ​​of the deviation properties were negative, which probably indicates a predominance of structural and chemical effects over physical effects. Five viscosity models were employed to fit the viscosity data. The VmE data were also correlated by the Prigogine-Flory-Patterson Theory (PFP Theory) and the Peng-Robinson-Stryjek-Vera Equation of State (PRSV EOS). Furthermore, a Fourier Transform Infrared (FT-IR) spectroscopy study was performed to explain the hydrogen bonding interactions. Lastly, theoretical calculations using Density Functional Theory (DFT) at B3LYP-GD3(BJ)/6–311++G(3df,2p) level of theory were performed to understand the inter-interactions between the compounds present in the mixtures. The FT-IR and computational results were in good agreement with the experimental data.

Thermodynamic study of choline chloride-based deep eutectic solvents with dimethyl sulfoxide and isopropanol

The thermodynamic properties of four binary mixtures of deep eutectic solvent (DES), i.e., ChCl/Gly (choline chloride + glycerol at a molar ratio of 1:2) and ChCl/EG (choline chloride + ethylene glycol at a molar ratio of 1:2) with two common co-solvents, i.e., dimethyl sulfoxide (DMSO) and isopropanol (IPA), were studied. Density and viscosity were determined at temperatures from 288.15 to 323.15 K, while measuring the enthalpy of mixing was performed at 308.15 and 318.15 K. The volumetric properties (i.e., excess molar volume and excess partial molar volume) and excess viscosities (i.e., viscosity deviation and logarithmic excess viscosity) were further calculated to investigate the effects of temperature, types of co-solvent and DES, and their contents on the non-ideal behavior of these systems, where the influence of treating the DES as a mixture of two components or a pseudo-component was discussed. The results of volumetric properties indicate that the combined influence of packing effects and H-bonding interactions between the DES and co-solvents led to the contraction of mixture volume, and the results of excess viscosities show H-bonding interactions play an important role in their variations. The results of enthalpy of mixing show that the mixing of DES with IPA is endothermic, while the mixing of DES with DMSO is exothermic. Furthermore, the nonrandom two-liquid (NRTL) model and Gibbs-Helmholtz equation were combined to represent the experimental results of the enthalpy of mixing, and the total average relative deviation (ARD) of all studied systems is 5.43%.

Experimental analysis of volumetric, acoustic, viscometric and optical properties of water with 1-amino-2-propanol, 1,2-diaminopropane and 1,3-diaminopropane at T=298.15 -318.15 K: Molecular Modelling by Graph, PFP and IR spectroscopy investigations

BackgroundLiquid mixtures are used as a solvent in most of the natural systems and chemical processes. Therefore, the physicochemical properties of liquid mixtures at different compositions and at different temperatures have a significant role in the optimization of chemical processes. The present report involves the analysis of the thermophysical properties of water (1) and amines (2). MethodsDensity, ρ, dynamic viscosity, η, refractive index, nD, and speed of sound, u, data were measured for binary mixtures of water (1) and amines (1A2P (1-amino-2-propanol), 1,2-DAP (1,2-diaminopropane) and 1,3-DAP (1,3-diaminopropane) (2) at five different temperatures (T = 298.15 to 318.15 K) and at 0.1 MPa pressure. Based on experimental data, the excess molar volume, VmE, deviation in dynamic viscosity, Δη, excess Gibbs free energy of activation, G*E, deviation in refractive index, ΔnD, excess ultrasonic speed, uE, excess isentropic compressibility, KsE, deviation in free volume, ΔVf, excess available volume, VaE, and excess intermolecular free length, LfE, were calculated and these evaluated properties were fitted to Redlich-Kister polynomial (R.K.). The VmE data was analyzed by Prigogine-Flory-Patterson (PFP) theory. The dynamic viscosity, η, values were studied by different correlations. The VmE and Δη data were also analyzed by Graph theoretical approach (GTA). Raman and FT-IR spectroscopic studies give important information about the intermolecular interactions present between unlike molecules water (1) and amines (2) which is also recognized by GTA. Significant findingsThe value of VmE and KsE values were found negative over the whole composition range, and it follow the sequence as: 1,2-DAP > 1,3-DAP > 1A2P with water at equimolar composition. GTA and PFP well supported the VmE data. GTA studies help in investigating the specific intermolecular interactions between unlike components. Further, Graph theory studies predicted OH—–NH interaction is dominant interaction among all interactions which were also supported by Raman and FTIR spectroscopic studies.

Thermo physical properties of 2-methyl-1-butanol with disubstituted ethanes at various temperatures and correlation with the jouyban–acree model

ABSTRACT The excess molar volume, excess isentropic compressibility, and deviation in viscosity have been investigated from density, speed of sound and viscosity measurements of three binary mixtures of 2-methyl-1-butanol (B) with 1,2–disubstituted ethanes (1,2–dichloroethane(B1), ethylenediamine (B2) and monoethanolamine (B3) over entire composition range at various temperatures of 303.15 K −313.15 K. The excess / deviation has been fitted by a Redlich-Kister equation and the results are discussed in terms of attractive forces and chemical forces. The excess properties are found to be either negative or positive depending on the physical and chemical forces and the nature of the liquid mixtures. These systems studied exhibit very strong cross-association through hydrogen bonding. Prigogine-Flory-Patterson (PFP) theory is applied to identify the predominant molecular interaction. Jouyban-Acree model, results are discussed in terms of mean relative deviation (MRDs) and individual relative deviation (IRD) between calculated and experimental densities, speeds of sound, and viscosities as an accuracy criterion.

Thermodynamic and molecular simulation analysis of molecular interactions between methyl 2–hydroxyisobutyrate + water or n–alkanol (C1–C2) mixtures

Methyl 2–hydroxyisobutyrate (HBM) is essential as a photoresist thinner in semiconductor fabrication. In this study, we examined the density and viscosity of HBM combined with water or alkanol (C1–C2) at a pressure of 0.1 MPa and temperatures ranging from 288.15 K to 323.15 K. Based on experimental data, we calculated the excess molar volume, as well as apparent, partial, and excess partial molar volumes, and deviations in viscosity. These derived thermodynamic properties were then modeled using the Redlich-Kister (RK) polynomial equation. The VmE values of HBM + water mixtures are more negative compared to HBM + alkanol mixtures because of the stronger H–bonding interactions in HBM–water than in HBM–alkanol. With increasing temperature, the VmEbecome more negative, whereas the Δη values lower with a temperature rise. The values for excess molar volume and deviation in viscosity were analyzed through a graph theoretical method. Additionally, the excess free energy of activation was determined from the viscosity data. FTIR spectral analysis validated the findings related to intermolecular interactions and the graph theoretical method. Lastly, molecular dynamics simulations shed light on the intermolecular interaction energies and their differences in the studied binary systems.

Viscometric, spectroscopic, and computational analyses of molecular interactions in binary mixtures of mesitylene with Heptan-1-ol and benzyl alcohol

Viscosities (ηexp) of binary combinations consisting of mesitylene (MES) paired with C7 aliphatic (heptan-1-ol, HepOH) and aromatic (benzyl alcohol, BnOH) alcohols were systematically measured across a range of temperatures (298.15 to 323.15 K; interval, 5 K) under atmospheric pressure conditions (0.10 MPa). Additionally, viscosity deviations (Δη) from ηexp values were calculated and fitted using the Redlich-Kister equation, encompassing the entire span of mole fractions. The ηexp values were compared against ηcal values predicted by the Grunberg-Nissan, Teja-Rice, and Andrade/DIPPR models. The molecular interactions of MES with HepOH or BnOH were also investigated using Fourier transform infrared spectroscopy. Furthermore, density functional theory, a quantum mechanical approach, was employed to assess intra- and intermolecular correlations among the constituent molecules within the binary mixtures. The findings of the study revealed that the molecular interactions in these mixtures are intricate and dependent on the composition of the mixture. In summary, mixtures of MES with BnOH exhibited stronger interactions than those with HepOH.

Detailed Analysis of the Effects of Viscosity Measurement Errors Caused by Heat Transfer during Continuous Viscosity Measurements under Various Temperature Changes and the Proposed Solution of a Non-Dimensional Parameter Called the Akpek Number

It is extremely important to gather the viscosity behavior of fluids accurately for industries and academia. There is no better method than viscosity measurement to detect changes in the specific characteristics of the materials. However, viscosity measurement is indeed a very sensitive process. In nature, fluids are involved in widely various containers, and they are affected by serious temperature deviations. It is a necessity for viscometers to have the capability to obtain accurate data from all types of containers of fluids even in serious temperature variations in order to understand the natural phenomena inside the fluids. Conventional viscometers mainly neglect the effect of sudden temperature deviations inside the fluids, or they need to use very expensive water bath systems that stabilize the temperature around the test fluids, which is not feasible at all. In this research, the effects of non-uniform temperature fields are analysed detailly to confirm that even in extremely limited amounts, serious viscosity and temperature deviations may occur. Experiments were performed in two parts. The first part was conducted using several thermocouples with different test fluids to find out the effects of thermal conduction and convection. For the second part, particle image velocimetry (PIV) was utilized to comprehend the flow movement within the test fluids. It was shown that even for small volumes and even in very controlled environments, an almost 35% viscosity measurement error (VME) occurs. Finally, as a solution to this problem, a new non-dimensional parameter called the Akpek number was proposed. The Akpek number enables the estimation of VMEs in any possible case. VME is a very crucial obstacle that has urgency to be illuminated by researchers and scientists to improve fluid characteristics. The main goal of this research is to illuminate the importance of this problem and offer a potential solution. The final results are supported by experimental data and numerical simulations using OpenFOAM.

Excess properties, spectral analyses, and CO2 capture performance of N-methyldiethanolamine + polyethylene glycol 300 binary system

Density (ρ) and viscosity (η) data of polyethylene glycol 300 (PEG300) + N-methyldiethanolamine (MDEA) binary system at T = (298.15–318.15) K with a step of 5 K were measured at P = 1005 hPa. After that, the experimental ρ and η values were correlated and predicted by several semi-empirical models. Meanwhile, the Jouyban-Acree model presented a better fitting for the density, and the McAllister four-body equation presented a better fitting for the kinematic viscosity. Based on the ρ and η values, excess molar volume (VmE), partial molar volume (V1¯ and V2¯), viscosity deviation (Δη), and excess Gibbs energy of activation of viscous flow (ΔG∗E) of PEG300 (1) + MDEA (2) binary system were systematically calculated and analyzed. These excess properties showed the predominance of intermolecular self-conjugation in PEG300 (1) + MDEA (2) binary system, and it was further demonstrated by various spectral characterizations. Importantly, the PEG300 + MDEA aqueous system was used for 5 CO2 absorption (room temperature)-desorption (371.15 K) cycles at a CO2 flow rate of 200 mL/min, with the average CO2 capture performance of 0.65 mol CO2/mol MDEA of per cycle, demonstrating excellent absorption capability, and remained stable throughout the entire cycle.

Probing molecular interactions in mixed system of green solvent ethyl lactate with oligomers of polyethylene glycol

Polyethylene glycol and its oligomers are potential hydrogen bond donors that act as a green, effective, non-toxic, non-corrosive and recyclable molecular component for extractive desulfurization of liquid fuels and variety of other applications. The aim of this investigation is to explore the molecular interactions via variations in viscosity that occur on mixing these glycols with green solvent ethyl lactate. Dynamic viscosities (η) for pure solvents and binary mixtures of ethyl lactate and glycols oligomers (mono/di/tri/tetra-ethylene glycol) were measured at varying temperatures T/(K) = (298.15–313.15; with an interval of 5). Viscosity deviations (Δη) along with excess thermodynamic parameters of activation for viscous flow as Gibbs free energy (ΔG∗E), Enthalpy (ΔH∗E) and Entropy (ΔS∗E) were derived from experimental data. The Δη and ΔG∗E values were further correlated using Redlich-Kister polynomial expression. The experimentally obtained viscosity values were compared with 10 generalised literature models (Arrhenius, Kendall, Kendall-Monroe, Grunberg-Nissan, Hind, Katti-Chaudhri, Heric, McAllister three-body, McAllister four-body and Jouyban-Acree models). The average standard deviation percentages (ASD %) were calculated for all the models to compare the quality of correlation with experimental data. The minimal ASD % for McAllister four-body and Jouyban-Acree models in the working systems indicate that the multiparameter relations have the best capability of reproducing the experimental values. The temperature induced variations were also discussed together with molecular interactions. Further, quantum mechanical density-functional theory and graph theoretical approaches were used to explore the extent of interactions among the components.

Experimental and theoretical evaluation of interactions in liquid mixtures consisting bio-based solvent and 2-alkoxyethanols through viscometric study

Viscometric properties provide a deep and meaningful insight of the various interactions taking place in binary liquid mixtures. Recently, bio-based solvents have been either employed directly as green solvents or as a key component for the production of new solvent systems that are potentially less toxic and more bio-compatible. In this paper, we report experimental values of dynamic viscosity (η) for binary systems of bio-based solvent (gamma-valerolactone) with 2-alkoxyethanols at different temperatures (298.15–313.15 K; interval, 5 K), covering the whole composition range under atmospheric pressure of 0.1 MPa. On the experimental basis, kinematic viscosity (ν), viscosity deviation (Δη) and excess Gibbs free energy of activation for viscous flow (ΔG∗E) have been calculated. The derived properties, Δη and ΔG∗E were fitted to Redlich-Kister polynomial equation to obtain binary adjustable parameters and standard deviations between experimental and estimated values. Further, the viscosity-composition data have been correlated with various approaches including no adjustable parameter (Bingham, Arrhenius, Kendall and Kendall-Monroe), one adjustable parameter, (Grunberg − Nissan, Hind et al. and Katti-Chaudhri), two adjustable parameter (McAllister three-body and Heric-Brewer) and three adjustable parameter (McAllister four-body and Jouyban-Acree) relations. Moreover, for all the predicted viscosity values, the standard deviation percentages (σ%) were calculated to compare the quality of correlations with experimental data. Furthermore, the Graph theory was employed to correlate experimental Δη values and to analyse the patterns of molecular aggregation in the studied mixtures. The DFT calculations were also performed in the support of graph theory. The observed Δη data suggests that the dissociation of self-associated structures of pure components is more dominating factor than hetero-association for all the studied binaries.

Volumetric and viscometric properties of aqueous choline chloride + methyldiethanolamine deep eutectic solvents

Amine-based deep eutectic solvents have the advantages of easy preparation, extremely low vapor pressure, stable biodegradation and high CO2 loading, which has become the most potential CO2 absorbent. In this work, the amine-based functionalized DES of choline chloride + methyldiethanolamine with different molar ratios were successfully prepared, and the densities and viscosities of DES aqueous solutions were measured from 303.15 K to 333.15 K. The effects of DES composition, water content and temperature on the excess molar volume, partial molar volume, apparent molar volume, limiting partial molar volume and viscosity deviation were investigated. The hydration and intermolecular interaction in DES solution were analyzed. The critical concentration of water in solution was determined under the premise of maintaining DES hydrogen bond network.

Some experimental and theoretical studies of diethylene glycol diethyl ether and 2-alkanol mixtures

Experimental density and dynamic viscosity data for the diethylene glycol diethyl ether +2-alkanol (C3 to C6) mixtures have been published at 293.15 K, 303.15 K, 313.15 K, and 323.15 K and at pressure of 0.1 MPa. Excess molar volume and deviation in dynamic viscosity were obtained from experimental data and correlated with Redlich–Kister equation, from the values obtained, the interaction forces were studied. Perturbed chain-statistical associating fluid theory equation of state was used for modeling the density for pure fluids and mixtures. Free volume theory coupled to Perturbed chain-statistical associating fluid theory equation of state was used to modeling the viscosity of pure fluids and mixtures; in the case of binary mixtures, we proposed a simple mixing rule and used the Pourabadeh et al. mixing rule. Good results in the prediction and correlation of experimental liquid density and dynamic viscosity for binary mixtures were obtained, 0.12% and 2.28%, respectively.

Volumetric, transport and acoustic properties of binary mixtures containing alkanol at 298.15–318.15 K

The measurement of density (ρ), viscosity (η) and ultrasonic speed (u) have been conducted at T = 298.15 K–318.15 K and at 0.1 MPa to study the intermolecular interactions between p–chlorotoluene with alkanol (C1–C2). These data were utilized to derive the excess properties like excess molar volume (VmE), deviation in viscosity (Δη), excess free energy of activation (ΔG*E), deviation in ultrasonic speed (Δu), and excess isentropic compressibility (κsE) for binary mixtures. Utilizing the VmE values, partial molar volume and excess partial molar volume were calculated. The Δη and κsE were investigated using theoretical models such as the Singh model and ab initio approach, which yielded interactional parameters that not only indicate the extent of unlike interactions and depolymerization of self–associated alkanol but also predicts the Δη and κsE for these systems. The conclusions of the ab initio approach were further validated by the Singh model for viscosity. The u data were further interpreted by various correlations and theories. Regarding correlation, Nomoto’s correlation demonstrated high predictive power for ultrasonic speed data, respectively, compared to other correlations. The resulting excess properties were fitted to Redlich–Kister polynomial equations. The VmE values were observed to be negative for p–chlorotoluene + alkanol systems at all temperatures. The study of the binary mixtures is significant because it sheds light on the nature of intermolecular interactions which has practical implications in areas such as chemical synthesis, solvent selection, and understanding the effects of solvents on reaction rates and product yields.

Viscosities of 1,2-DAP + alkyl acetates binary liquid mixtures at T = 298.15–318.15 K: Theoretical interpretation by Graph theoretical approach (GTA) and Bloomfield and Dewan (BFD) model

The liquid mixtures are used as a solvent in most of the natural systems and chemical processes. Therefore, the physicochemical properties of liquid mixtures at different compositions and at different temperatures have a significant role in the optimization of chemical processes. In the present report, the dynamic viscosity (η) of 1,2-DAP (1,2-Diaminopropane) (1) with AAc (alkyl acetates) (C1-C4) (2) were measured at different temperatures (T = 298.15 to 318.15 K) at pressure 0.1 MPa. Deviation in dynamic viscosity, Δη, and excess Gibbs free energy of activation, G∗E, for these binary mixtures were calculated from measured dynamic viscosity data and fitted to Redlich-Kister polynomial equation (R.K.). Δη data were examined in terms of the Bloomfield and Dewan (BFD) model and Graph theoretical approach (GTA) to study the intermolecular interactions in binary mixtures. Further, different correlation like Hind-McLaughlin-Ubbelohde, Bingham, Arrhenius, Kendall, Heric-Brewer, Kendall-Monroe, Tamura-Kurata, Lulian, Grunberg-Nissan, Krishnan-Laddha Frenkel, Katti-Chaudhari, Heric and McAllister were used to correlate η values.

Dynamic viscosity prediction using artificial intelligence for an antifreeze containing MWCNT–alumina hybrid nanopowders

This paper investigates the impact of Solid Volume Fraction (SVF) and temperature on the dynamic viscosity of a hybrid antifreeze composed of MWCNTs and aluminum oxide in a mixture of water (80%) and ethylene-glycol (20%). An Artificial Neural Network (ANN) is used to predict the viscosity of the nanofluid, which was generated at different SVFs ranging from 0.25% to 1% and temperatures ranging from 25 °C to 50 °C. This study aims to establish a correlation between viscosity and input parameters in the antifreeze. Results demonstrate that Shear Rate (SR) and SVF have opposite effects on the viscosity of the nanofluid. Increasing SVF leads to a strong increase in viscosity deviation and higher mean values of viscosity while increasing SR results in a sharp decline in both the mean value and variation of the viscosity. The temperature has a smaller impact on viscosity variance than SR and SVF. The proposed ANN model with a two-layer network and 13 neurons having nonlinear activation functions in the hidden layer shows an accurate prediction of viscosity versus inputs. The proposed methodology offers an improvement of up to 10 times in predicting viscosity accuracy as compared to GMDH and decision tree techniques. The findings of this study can have important implications for the design of heat exchangers using nanofluids especially in portable devices.

Studying of Acoustical Parameters of Some Binary Liquid Mixture at 303.15 K and 3 M. Hz

The ultrasonic velocity, density and viscosity of 1,4- dioxane with alkanols systems have been measured experimentally at 303.15 K over the frequency 3 M. Hz. From these three values, we have calculated thermodynamic and excess thermodynamic parameters such as adiabatic compressibility, deviation in adiabatic compressibility, molar volume excess molar volume, free length, excess free length, Viscosity, deviation in viscosity, internal pressure ,excess internal pressure, acoustic impedance, excess acoustic impedance, excess sound velocity, Rao,s constant, Wada constant, relaxation time and relaxation strength of binary liquid mixture to interpret the nature of the interactions taking place in the binary liquid mixtures. The results analyzed in the sight of molecular interaction between the components. The interaction resulting in the interstitial accommodation of 1, 4- dioxane into alkanols are the predominant factor over dipole-dipole interaction.