Showing papers on "Viscometer published in 2021"

Experimental Investigation on Stability, Viscosity, and Electrical Conductivity of Water-Based Hybrid Nanofluid of MWCNT-Fe2O3.

Abstract: The superiority of nanofluid over conventional working fluid has been well researched and proven. Newest on the horizon is the hybrid nanofluid currently being examined due to its improved thermal properties. This paper examined the viscosity and electrical conductivity of deionized water (DIW)-based multiwalled carbon nanotube (MWCNT)-Fe2O3 (20:80) nanofluids at temperatures and volume concentrations ranging from 15 °C to 55 °C and 0.1–1.5%, respectively. The morphology of the suspended hybrid nanofluids was characterized using a transmission electron microscope, and the stability was monitored using visual inspection, UV–visible, and viscosity-checking techniques. With the aid of a viscometer and electrical conductivity meter, the viscosity and electrical conductivity of the hybrid nanofluids were determined, respectively. The MWCNT-Fe2O3/DIW nanofluids were found to be stable and well suspended. Both the electrical conductivity and viscosity of the hybrid nanofluids were augmented with respect to increasing volume concentration. In contrast, the temperature rise was noticed to diminish the viscosity of the nanofluids, but it enhanced electrical conductivity. Maximum increments of 35.7% and 1676.4% were obtained for the viscosity and electrical conductivity of the hybrid nanofluids, respectively, when compared with the base fluid. The obtained results were observed to agree with previous studies in the literature. After fitting the obtained experimental data, high accuracy was achieved with the formulated correlations for estimating the electrical conductivity and viscosity. The examined hybrid nanofluid was noticed to possess a lesser viscosity in comparison with the mono-particle nanofluid of Fe2O3/water, which was good for engineering applications as the pumping power would be reduced.

Influence of TiO2 on viscosity, phase composition and structure of chromium-containing high-titanium blast furnace slag

Abstract: The viscous flow of CaO–SiO2–Al2O3–MgO–TiO2–Cr2O3 slag (CaO/SiO2 = 1.1, Cr2O3 = 0.5 mass%) were investigated to promote understanding of the effect of TiO2 addition on the viscous behavior of chromium-containing vanadium-titanium blast furnace slag. The viscosity of the slag was measured using a rotating crucible viscometer. Raman spectroscopy analysis was performed to correlate the viscosity to slag structure. The viscosity of slag was found to significantly decrease with increasing TiO2 content at a fixed basicity. It is because the Ti4+ continuously detached from the network structure, the content of [Ti2O6]4- decreased, and the content of [TiO4]4- tetrahedral monomer increased, which made the slag structure simplified. Consequently, the polymerization degree of the slag decreases with increasing TiO2 content. The variation in slag structure is consistent with the change in measured viscosity.

Precise Method to Estimate the Herschel-Bulkley Parameters from Pipe Rheometer Measurements

Abstract: Accurate characterization of the rheological behavior of non-Newtonian fluids is critical in a wide range of industries as it governs process efficiency, safety, and end-product quality. When the rheological behavior of fluid may vary substantially over a relatively short period of time, it is desirable to measure its viscous properties on a more continuous basis than relying on spot measurements made with a viscometer on a few samples. An attractive solution for inline rheological measurements is to measure pressure gradients while circulating fluid at different bulk velocities in a circular pipe. Yet, extracting the rheological model parameters may be challenging as measurement uncertainty may influence the precision of the model fitting. In this paper, we present a method to calibrate the Herschel-Bulkley rheological model to a series of differential pressure measurements made at variable bulk velocities using a combination of physics-based equations and nonlinear optimization. Experimental validation of the method is conducted on non-Newtonian shear-thinning fluid based on aqueous solutions of polymers and the results are compared to those obtained with a scientific rheometer. It is found that using a physics-based method to estimate the parameters contributes to reducing prediction errors, especially at low flow rates. With the tested polymeric fluid, the proportion difference between the estimated Herschel-Bulkley parameters and those obtained using the scientific rheometer are −24% for the yield stress, 0.26% for the consistency index, and 0.30% for the flow behavior index. Finally, the computation requires limited resources, and the algorithm can be implemented on low-power devices such as an embedded single-board computer or a mobile device.

Viscosity of binary refrigerant mixtures of R32 + R1234yf and R32 + R1243zf.

Abstract: Viscosity measurements of six binary mixtures of R32+R1234yf and R32+R1243zf at different compositions were conducted in the homogenous liquid and gas phases with a vibrating-wire viscometer in the temperature range from (254 to 383) K and pressures from (1 to 8) MPa. The measurement system was verified with the measurements of pure carbon dioxide and R32 in homogenous liquid and gas phases. The relative combined expanded uncertainties (k = 2) in the experimental viscosity of the mixtures are generally from 3.2% to 5.0%. The measured viscosities agree with the calculations of the extended corresponding state model implemented in the software package REFPROP 10.0 within 10% and mainly within 5%. The parameters of the residual entropy scaling model incorporating cubic-plus-association equation of state (RES-CPA model) for the viscosity of pure R1243zf and binary R32 + R1243zf mixture were determined. The relative deviation of the measured viscosities from values calculated with the RES-CPA model is mainly within 6% in the liquid phase and 10% in the gas phase.

Effect of Powder/Water Ratio Variation on Viscosity, Tear Strength and Detail Reproduction of Dental Alginate Impression Material (In Vitro and Clinical Study).

Abstract: Background: Alginate impression is a common dental polymeric material, presented as powder to be mixed with water. Aim: 1. To analyze the effect of alginate powder/water ratio variation on viscosity, tear strength and detail reproduction by in vitro tests, and 2. To evaluate this variation’s effect on patients’ impressions. Materials and methods: Two commercial alginate products were mixed in different viscosities. Viscosity was measured by a viscometer. For the tear strength test, V-shaped specimens were used. For detail reproduction, a die with three scribed lines was used. Clinical dental impressions were examined by stereomicroscope. Results: The alginate specimens mixed with a higher powder/water ratio showed a higher viscosity and tear strength compared to those with a lower powder/water ratio. Both alginate mixtures reproduced two scribed lines in a detail reproduction test. On the other hand, no clear clinical difference was detected when examining dental impressions mixed with a different powder/water ratio. Conclusion: Although increasing the powder/water ratio of mixed alginate raised the resultant viscosity and tear strength by an in vitro test, clinically, no clear difference in tearing was detected. Detail reproduction was minimally affected by the variation in powder/water ratio.

Mechanically flexible viscosity sensor for real-time monitoring of tubular architectures for industrial applications

Abstract: This publication is based on the work supported by King Abdullah University of Science and Technology (KAUST) and the Research and Development Centre of Saudi Aramco company.

Effect of CaCl2 Addition on the Viscosity of CaO–SiO2–FeOx Steelmaking Slag System

Abstract: In order to investigate the effect of CaCl2 addition on the viscosity of BOF steelmaking slag, a rotating viscometer was employed to measure the viscosities of different slags with different basicity and FeOx contents. Raman spectra were applied to understand the change of the microstructure of the CaO–SiO2–FeOx(–CaCl2) slag system, and the activation energy of the slag system was also considered to reveal the influential mechanism of CaCl2 on the slag viscosity. It was found that CaCl2 can effectively reduce the slag viscosity and the critical crystallization temperature (TCR). The rise of slag basicity can decrease the viscosity of the slag system at a high temperature (T > TCR), while it is not favorable to a lower viscosity when T < TCR. Due to the supply of free oxygen ions, both higher slag basicity and higher FeOx content can simplify the structure of silicates, no matter whether CaCl2 is added. Besides, a [FeO4]-tetrahedron peak is also found in the Raman spectra, but its variation is very small. Further investigation is still needed for the effect of FeOx on the microstructures of the slag system.

Development of Laser-Induced Graphene-Based Automated Electro Microfluidic Viscometer for Biochemical Sensing Applications

Abstract: In fluid rheological studies, viscosity measurement is one of the most significant phenomena leveraged in a variety of studies. Viscometers are broadly employed in a wide range of sensing and monitoring applications, such as biochemical diagnostics and numerous adulteration detections. Therefore, it is pertinent to develop a miniaturized, automated, and cost-effective device that can measure the fluid viscosity from small samples. In this work, for fluid viscosity measurements, a new low-cost automated electro-microfluidic viscometer (EMV) has been fabricated on a hydrophilic laser-induced graphene (LIG) platform with integrated electronics to monitor viscosity from a small sample of fluid of $1.5~\mu \text{L}$ . The principle of operation of the fabricated device is based on the modified Hagen–Poiseuille equation, which imitates the Ostwald viscometer. Under laminar flow, the proposed standalone and portable device automatically evaluates the travel time of fluid with high accuracy. This travel time was used to obtain viscosity accurately of various fluids, such as water, milk, and acetic acid, with a minimum error of up to ±1.08%. Overall, the device provides a pathway for a convenient, robust, and plug-and-play platform for different applications, including various adulteration monitoring and biosensing.

Sensorless Self-Excited Vibrational Viscometer with Two Hopf Bifurcations Based on a Piezoelectric Device.

Abstract: In this study, we propose a high-sensitivity sensorless viscometer based on a piezoelectric device. Viscosity is an essential parameter frequently used in many fields. The vibration type viscometer based on self-excited oscillation generally requires displacement sensor although they can measure high viscosity without deterioration of sensitivity. The proposed viscometer utilizes the sensorless self-excited oscillation without any detection of the displacement of the cantilever, which uses the interaction between the mechanical dynamics of the cantilever and the electrical dynamics of the piezoelectric device attached to the cantilever. Since the proposed viscometer has fourth-order dynamics and two coupled oscillator systems, the systems can produce different self-excited oscillations through different Hopf bifurcations. We theoretically showed that the response frequency jumps at the two Hopf bifurcation points and this distance between them depends on the viscosity. Using this distance makes measurement highly sensitive and easier because the jump in the response frequency can be easily detected. We experimentally demonstrate the efficiency of the proposed sensorless viscometer by a macro-scale measurement system. The results show the sensitivity of the proposed method is higher than that of the previous method based on self-excited oscillation with a displacement sensor.

Simultaneous Measurements of Temperature and Viscosity for Viscous Fluids Using an Ultrasonic Waveguide.

Abstract: The characterisation and monitoring of viscous fluids have many important applications. This paper reports a refined ‘dipstick’ method for ultrasonic measurement of the properties of viscous fluids. The presented method is based on the comparison of measurements of the ultrasonic properties of a waveguide that is immersed in a viscous liquid with the properties when it is immersed in a reference liquid. We can simultaneously determine the temperature and viscosity of a fluid based on the changes in the velocity and attenuation of the elastic shear waves in the waveguide. Attenuation is mainly dependent on the viscosity of the fluid that the waveguide is immersed in and the speed of the wave mainly depends on the surrounding fluid temperature. However, there is a small interdependency since the mass of the entrained viscous liquid adds to the inertia of the system and slows down the wave. The presented measurements have unprecedented precision so that the change due to the added viscous fluid mass becomes important and we propose a method to model such a ‘viscous effect’ on the wave propagation velocity. Furthermore, an algorithm to correct the velocity measurements is presented. With the proposed correction algorithm, the experimental results for kinematic viscosity and temperature show excellent agreement with measurements from a highly precise in-lab viscometer and a commercial resistance temperature detector (RTD) respectively. The measurement repeatability of the presented method is better than 2.0% in viscosity and 0.5% in temperature in the range from 8 to 300 cSt viscosity and 40 to 90 °C temperature.

Low-consumption photoacoustic method to measure liquid viscosity.

Abstract: Viscosity measurement is important in many areas of biomedicine and industry. Traditional viscometers are usually time-consuming and require huge sample volumes. Microfluidic viscometry may overcome the challenge of large sample consumption but suffers from a long process time and a complicated structure design and interaction. Here, we present a photoacoustic method that measures the liquid viscosity in a simple microfluidic-based tube. This new viscosity measurement method embraces fast detection speed and low fluid consumption, offering a new tool for efficient and convenient liquid viscosity measurement in a broad range of applications.

Application of FTIR-ATR Spectrometry in Conjunction with Multivariate Regression Methods for Viscosity Prediction of Worn-Out Motor Oils

Abstract: Viscosity is considered to be a key factor in the quality of lubrication by oil and engine manufacturers and is therefore one of the most monitored parameters of lubricants. FTIR (Fourier-transform infrared) spectrometry in combination with Partial Least Squares (PLS) and Principal Component Regression (PCR) was therefore proposed and tested as an alternative to the standardized method for determining the kinematic viscosity at 100 °C with an Ubbelohde capillary viscometer (CSN EN ISO 3104) of worn-out motor oil grade SAE 15W-40. The FTIR-PLS model in the spectral region of 1750–650 cm−1 with modification of the spectra by the second derivative proved to be the most suitable. A significant dependence of R = 0.95 was achieved between the viscosity values of 190 samples of worn-out motor oils, which were determined by a standardized laboratory method, and the values predicted by the FTIR-PLS model. The Root Mean Square Error of Calibration (RMSEC) parameter reached 0.148 mm2s−1 and the Root Mean Square Error of Prediction (RMSEP) parameter reached 0.190 mm2s−1. The proposed method for determining the kinematic viscosity at 100 °C by the FTIR-PLS model is faster compared to the determination according to the CSN EN ISO 3104 standard, requires a smaller amount of oil sample for analysis and produces less waste chemicals.