Solid Particle Volume Research Articles

Effects of using a finned cylindrical cooler in the nano-enhanced cooling channel on the exergetic performance of a PV/TEG-coupled system

ABSTRACT In this study, three different nano-enhanced channel models were integrated into the 3D photovoltaic (PV)/thermoelectric generator (TEG) system and the effect of the channel models on the PV/TEG system performance was examined. The flat rectangular channel, Model 1 while the cylindrical and fin-reinforced cylindrical object accommodated in the flat rectangular channel are defined as Model 2 and Model 3, respectively. A comparison of water and ternary nanofluid with various nanoparticle (solid particle volume fraction between 0.01 and 0.03) loading was performed in each channel model. In addition, impacts of cooling fluids at different inlet temperatures (Tg between 25°C and 12.5°C) were considered in the simulations. Among different cooling channels, lowest PV cell temperature and the highest PV output power were obtained in Model 3. The highest PV power (0.51 W) was obtained with Model 3 with ternary nanofluid (%3 volume fraction) at Tg = 12.5°C. This value is is 3.66% and 4.03% higher than Model 2 and Model 1, respectively. Under the same conditions, TEG output power reached its highest value with Model 2 and it was followed by Model 1 and Model 3, respectively. With the reinforcement of fins to the cylindrical object, an improvement in thermal performance was achieved, but a decrease in total output power was observed.

Particle-assisted formation of oil-in-liquid metal emulsions.

Gallium-based liquid metals (LM) have surface tension an order of magnitude higher than water and break up into micro-droplets when mixed with other liquids. In contrast, silicone oil readily mixes into LM foams to create oil-in-LM emulsions with oil inclusions. Previously, the LM was foamed through rapid mixing in air for an extended duration (over 2 hours). This process first results in the internalization of oxide flakes that form at the air-liquid interface. Once a critical fraction of these randomly shaped solid flakes is reached, air bubbles internalize into the LM to create foams that can internalize secondary liquids. Here, we introduce an alternative oil-in-LM emulsion fabrication method that relies on the prior addition of SiO2 micro-particles into the LM before mixing it with the silicone oil. This particle-assisted emulsion formation process provides a higher control over the composition of the LM-particle mixture before oil addition, which we employ to systematically study the impact of particle characteristics and content on the emulsions' composition and properties. We demonstrate that the solid particle size (0.8 µm to 5 µm) and volume fraction (1% to 10%) have a negligible impact on the internalization of the oil inclusions. The inclusions are mostly spherical with diameters of 20 to 100 µm diameter and are internalized by forming new, rather than filling old, geometrical features. We also study the impact of the particle characteristics on the two key properties related to the functional application of the LM emulsions in the thermal management of microelectronics. In particular, we measure the impact of particles and silicone oil on the emulsion's thermal conductivity and its ability to prevent deleterious gallium-induced corrosion and embrittlement of contacting metal substrates.&#xD.

Nanofluid heat transfer enhancement in microchannels: Investigating phases interactions using multiphase Eulerian model

This study employs a robust multiphase Eulerian model to mimic heat transfer enhancement using nanofluids in a circular microchannel. Unlike the Eulerian models reported in the literature, the current model incorporates phase interactions, and its accuracy is significantly improved by integrating collision viscosity, kinetic viscosity, and frictional viscosity. Comparative analysis against other models like mixture and discrete phase models demonstrates superior performance of the current model, particularly for solid particle volume fractions exceeding 1 %. The model evaluates water-based nanofluids (Ag NPs, MgO, ZnO, Al2O3, ZrO2, SiO2) in circular microchannels. Ag NPs/water excels at low volume fractions and high Reynolds numbers, while MgO/water performs better at higher volume fractions. Moreover, the analysis of the Euler number indicates a decreasing trend with increasing Reynolds number across all nanofluids. However, no notable variation in the Euler number is observed when maintaining constant volume fraction and Reynolds number. Ultimately, the model is applied to obtain bulk fluid properties, such as viscosity and thermal conductivity, after suspending the nanoparticles. Subsequently, these properties were incorporated into the single-phase model. Utilizing these derived bulk properties was found to substantially enhance the accuracy of the single-phase model, demonstrating its reliability by yielding results within 13.52 % of experimental data.

Investigation on drawdown process of light-floating particles in a pilot scale cup-shaped blade agitator

The novel cup-shaped blade agitator with pilot scale was successfully applied in light-floating particles drawdown dispersion under high solid content (40 vt.%) for the first time. The drawdown dispersion effect of cup-shaped blade agitator was systematically investigated, by integrating the CFD simulation, the research unveils the impact mechanisms of flow conditions within the agitator on particle drawdown and dispersion, under various structural and operational parameters of the cup-shaped blade (CB) impeller. The optimum structure for CB was determined as CB2, with impeller deflection angle of -30°, and impeller diameter of 0.43 m. Under this structure, the CB agitator exhibits the best performance and can complete drawdown dispersion of light-floating particles at high solid concentration exceeding 40 vt.%. Besides, at lower solid particle volume concentration (Cv), both Njd and Pjd increase with increasing Cv. Interestingly, after Cv exceeds 10%, Njd and Pjd decrease as Cv continues to rise. Comparing with traditional impeller RT and PBT, the CB impeller is more competitive. Finally, dimensionless correlations of Njd and Pjd were established to provide practical guidance for application and optimization of CB agitator.

Efficient cooling system design by using different shaped nanoparticles and rotating cylinders in channel system for photovoltaic thermal management

Research focusing on improving the efficiency and performance of renewable energy systems requires the development of cooling systems (CSs) with effective solutions, including photovoltaic (PV) thermal management. The current work proposes a unique cooling method that uses double rotating cylinders (RCs) and different shaped alumina nanoparticles (NP; spherical, blade, brick, and cylindrical) in water for conductive panel’s cooling channel. The numerical study is performed for different values of Reynolds number (Re: 100–600), rotational Re (Rew: 0–20), size of the cylinders (Rc: 0.01H–0.2H), and solid particle volume fractions (svf: 0–0.03). It is observed that vortex size and numbers behind the cylinders can be controlled by varying Re and Rew. A 16 °C temperature drop of the panel is achieved at the highest Re at svf = 0.03. When rotations are active, the average Nu increases 99% and 37% for water and nanofluid (NF) at Rew = 20 and Re = 250 while temperature drops of 15 °C and 7.5 °C are obtained. The highest performance coefficient (PEC) is obtained as PEC = 1.38 when NF is used at Rew = 15. Large cylinders results in lower PEC values. When rotations are not active, the average Nu rises by about 26.8%, 13.5%, 12.8%, and 3.5% for cylindrical, blade, brick, and spherical-shaped particles while average cell temperature drops by about 5.5 °C, 4.5 °C, 4.3 °C, and 1 °C. The highest PEC value is obtained as 1.23 when cylindrical particles at the highest loading are used for stationary cylinders. Proper orthogonal-based model is considered for estimation of spatially varying panel temperature.

Considerations for Ionic Diffusion in Slurry Electrolytes for Redox Flow Batteries

Slurry electrodes have been proposed as a means to enhance the scalability of hybrid redox flow battery (RFB) chemistries for better usability in utility scale energy storage applications1–3. In conventional hybrid RFB’s, scalability is limited due the spatial constraints of the flow cell and the metal deposited by the negative half-reaction on charge1. By using a slurry electrode, the solid metal can be deposited onto electrically conductive particles dispersed in the electrolyte instead of on the stationary electrode within the flow cell. In this way, hybrid RFB chemistries can achieve the same scalability as more commonly studied true RFB chemistries, such as all-vanadium. Due to the high abundance, low cost, and low toxicity of iron electrolytes, the all-iron RFB chemistry is of particular interest for use with a slurry electrode2,4. The usefulness of the slurry electrode depends on the current distribution of the plating reaction. To successfully decouple the storage and power capacities of the RFB and thus enhance its scalability5, the faradaic current of the plating reaction must occur predominantly on the mobile slurry particles, as opposed to on the stationary current collector1. This current distribution is dependent on a variety of factors, such as the applied overpotential, the electrical conductivity of the slurry, the ionic conductivity of the electrolyte, the kinetics of the reaction, and the rate of ionic mass transport to reaction sites. Ionic mass transport in electrolytes containing slurry electrodes may differ from ionic transport in neat electrolyte in interesting and important ways. Due to the volume fraction of the electrolyte occupied by solid particles, the effective concentration of the ionic species may be lower than in neat electrolyte. Further, the solid particle volume fraction hinders ionic diffusion by introducing diffusion path tortuosity. This effect is more severe in higher slurry particle loadings.In this work, the effect of varying dispersed solid particle loading on ionic diffusivity is investigated via voltammetry using a rotating disk electrode. The diffusivities of ionic iron species are measured as a function of the volume fraction of solids dispersed in the electrolyte. Comparisons with the Bruggeman correlation6,7 are made and amendments to the Levich equation are considered.(1) Petek, T. J.; Hoyt, N. C.; Savinell, R. F.; Wainright, J. S. Slurry Electrodes for Iron Plating in an All-Iron Flow Battery. J. Power Sources 2015, 294, 620–626. https://doi.org/10.1016/j.jpowsour.2015.06.050.(2) Petek, T. J. Enhancing the Capacity of All-Iron Flow Batteries: Understanding Crossover and Slurry Electrodes. Ph.D. Thesis 2015, No. May.(3) Narayanan, T. M.; Zhu, Y. G.; Gençer, E.; McKinley, G.; Shao-Horn, Y. Low-Cost Manganese Dioxide Semi-Solid Electrode for Flow Batteries. Joule 2021, 5 (11), 2934–2954. https://doi.org/10.1016/j.joule.2021.07.010.(4) Dinesh, A.; Olivera, S.; Venkatesh, K.; Santosh, M. S.; Priya, M. G.; Inamuddin; Asiri, A. M.; Muralidhara, H. B. Iron-Based Flow Batteries to Store Renewable Energies. Environ. Chem. Lett. 2018, 16 (3), 683–694. https://doi.org/10.1007/s10311-018-0709-8.(5) Weber, A. Z.; Mench, M. M.; Meyers, J. P.; Ross, P. N.; Jeffrey, T.; Liu, Q. Redox Flow Batteries , a Review Environmental Energy Technologies Division , Lawrence Berkeley National Laboratory , Department of Mechanical , Aerospace and Biomedical Engineering , University of Tennessee , Department of Chemical Engineering , McGill Un. 1–72.(6) Tjaden, B.; Cooper, S. J.; Brett, D. J.; Kramer, D.; Shearing, P. R. On the Origin and Application of the Bruggeman Correlation for Analysing Transport Phenomena in Electrochemical Systems. Curr. Opin. Chem. Eng. 2016, 12, 44–51. https://doi.org/10.1016/j.coche.2016.02.006.(7) Chung, D. W.; Ebner, M.; Ely, D. R.; Wood, V.; Edwin García, R. Validity of the Bruggeman Relation for Porous Electrodes. Model. Simul. Mater. Sci. Eng. 2013, 21 (7). https://doi.org/10.1088/0965-0393/21/7/074009.

Particle size distribution at Ocean Station Papa from nanometers to millimeters constrained with intercomparison of seven methods

Particle size distribution (PSD) is a fundamental property that affects almost every aspect of the marine ecosystem, including ecological trophic interactions and transport of organic matter and trace elements. We measured PSDs using a suite of seven instruments in waters near Ocean Station Papa in the Northeast Pacific Ocean. These instruments and their sizing ranges are: Laser In-Situ Scattering and Transmissometer (LISST)-Volume Scattering Function meter (VSF) and Multispectral Volume Scattering Meter (MVSM), both sizing particles from 0.02 µm to 2000 µm; the LISST-100X, from 3 µm to 180 µm; the ViewSizer, from 0.3 µm to 2 µm; the Coulter Counter, from 2 µm to 40 µm; the Imaging Flow CytoBot (IFCB), from 5 µm to 100 μm; and the underwater vision profiler (UVP), from 100 µm to 2000 µm. Together, they cover an unprecedented size range spanning 5 orders of magnitude from 20 nm to 2 mm. The differences in size definition for the different instruments cause biases in comparing PSDs. The absolute differences in PSDs, after correcting for mean biases, were less than a factor of 3 among all the instruments, and within 50% among LISST-100X, LISST+MVSM, Coulter Counter and IFCB. We also found that particles of sizes <50 µm were not very porous; however, porosity must be considered for particles >50 µm. The merged PSDs, ranging from 0.02 µm to 2000 µm, showed little variation in the PSD slope in the upper 75 m of the water column even though the total number of particles decreased with depth. While submicrometer particles are numerically dominant, particles of sizes 1 µm to 100 µm account for 70–90% of the solid volume of particles. We expect that the results of this study will lead to improved estimates of mass and carbon flux in the study area.

Three-Dimensional Analysis of the Thermal Behavior of Alumina-Water Nanofluid Inside Hexagonal and Octagonal Enclosed Domain

The current work focused on the study of the laminar and steady free convection of Aluminum Oxide / Water nanofluid inside cavities. Two different cavities have the same volume but different overall surface area and count of walls are studied. These cavities are heated differentially on the vertical square side walls which of identical area and dimensions for both cavities. The other vertical walls of these cavities have hexagonal and octagonal shapes. The first cavity has eight walls while the second has ten walls. The study accomplished for solid particles volume fraction and Rayleigh number ranges of (φ = 0.01, 0.03, 0.05) and (103 ≤ Ra ≤ 106). The study interested highly by the effect of the cavity geometry parameters including the lateral cross section, the height, the number of walls on the flow and heat transfer. Other flow parameters are recognized on the fluid flow and heat transfer fields like the nanoparticles volume fraction and the Rayleigh number. The results indicated that the surface area increase by means the additional walls has an observed effect on guiding the results. Where the octagonal cavity has better enhancement in heat transfer especially at (Ra=104 and 105). The percent increase in Nu over the hexagonal cavity is (0.6, 0.8, 0.7, 0.3) for the specified Ra range.

A novel method of discharge capacity prediction based on simplified electrochemical model-aging mechanism for lithium-ion batteries

Obtaining the State of Health of lithium-ion batteries and mastering its degradation laws are crucial for the utilization of Electric Vehicles. However, the prediction of discharge capacity of lithium-ion batteries requires high accuracy, which is subject to the variation of cells and the uncertainty of operating conditions. In this work, a discharge capacity prognostics method for lithium-ion batteries is developed based on a simplified electrochemical coupled aging mechanism model. Firstly, the solid-phase diffusion process is analyzed by using a simplified electrochemical model, and the particle rupture stress at different C rates is obtained. Then, based on the aging mechanisms in terms of Solid Electrolyte Interphase (SEI) layer growth model and particle volume expansion model, the SEI growth rate and correlated aging kinetics parameters are optimized by using particle swarm optimization algorithm. Finally, combined with the further analysis of aging mechanisms and variation of model parameters at early, middle, and late stage of degradation, the developed discharge capacity prediction method is verified at separate stages for batteries at 1C, 2C and 3C respectively, with the average relative error of full life cycle no more than 4 %.

Study of the effect of solid particle volume fraction on cavitation characteristics in a centrifugal pump

Study of the effect of solid particle volume fraction on cavitation characteristics in a centrifugal pump

Optimal Configuration of Gas Solid Separation Equipment Using Mixed Integer Nonlinear Programming

The separation of solid particles from gas-solid process streams is an important unit operation in many chemical processes. Out of the many different types of separation equipment that are used for gas-solid separation, cyclone separators are widely used for their operational flexibility, efficiency and capital cost. This study focused on the design of an optimal configuration for several cyclones used in a fertilizer plant. The granulation step in the fertilizer plant leads to using different size cyclones and a different number of cyclones in series or parallel or a mix of both arrangements. A Mixed Integer Nonlinear Programming (MINLP) model is formulated to find the best cyclone arrangement with the optimal number of cyclones and dimensions from several combinations of 1D3D and 2D2D cyclones arranged in parallel-series for a high volume and heavy loading of solid particles. The objective function was to minimize the total cost, including the operating cost and the capital cost. The results indicated that a maximum of 90% efficiency is achieved with a parallel-series arrangement of 1D3D and 2D2D cyclones to be an optimal configuration for the maximum reduction in pollution level.

Quasi-steady-state modelling and characterization of diffusion-controlled dissolution from monodisperse prolate and oblate spheroidal particles

A quasi-steady-state model of the dissolution of a single prolate or oblate spheroidal particle has been developed based on the exact solution of the steady-state diffusion equation for mass transfer in an unconfined media. With appropriate treatment of bulk concentration, the model can predict the detailed dissolution process of a single particle in a container of finite size. The dimensionless governing equations suggest that the dissolution process is determined by three dimensionless control parameters, initial solid particle concentration, particle aspect ratio and the product of specific volume of solid particles and saturation concentration of the dissolved substance. Using this model, the dissolution processes of felodipine particles are analysed in a broad range of space of the three control parameters and some characteristics are identified. The effects of material properties indicated by the product of specific volume and saturation concentration are also analysed. The model and the analysis are applicable to the system of monodisperse spheroidal particles of the same shape.

Effect of Cr2O3 on Physicochemical Properties of CaO-SiO2-FetO Slags during BOF Smelting Process of Chromium-Bearing Iron

The productivity of basic-oxygen-furnace (BOF) smelting process is directly affected by the slag-forming speed during the initial stage of converter. Therefore, it is essential to study the effect of different Cr2O3 content on the physicochemical properties of the primary slag in the smelting process of chromium-bearing semi-steel. In this work, Factsage8.1 software, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and a high-temperature melting point tester were used to study the effects of different Cr2O3 content on the melting temperature, solidification behavior, mineral composition, and other physicochemical properties of the CaO-SiO2-FetO system. The results showed that the melting temperature of slag samples increased from 1223 °C to 1354 °C as Cr2O3 increased from 0 wt% to 9.09 wt%. With the increase of Cr2O3, the content of CaFeSi2O6 decreased. Moreover, due to the addition of Cr2O3, the chromium-bearing spinel solid solution (Fe(Fe,Cr)2O4) began to form in the slag. Furthermore, Cr2O3 promoted the increase in the volume of free solid particles in the slag, resulting in an increase in slag viscosity. All in all, the increase of Cr2O3 content in the CaO-SiO2-FetO system will adversely affect the semi-steel steelmaking process.

Sustainable wastewater management from shale oil production wells: emerging opportunities and barriers

During the production from shale oil formations, the produced water has been dedicated to different procedures such as chemical enhanced oil recoveries, drilling mud making (e.g., for various purposes of lubrication and cooling) and hydraulic fracturing. One of the main challenges of wastewater treatment corresponds to (TDS) total dissolved solids. To measure the required water needed for different processes, it is necessary to proceed with every step saving and then make an average to calculate the required freshwater. In this regard, we have selected five different oil wells with the same rock and reservoir characteristics. SOW#3 has the highest rate of treatment (26%) and SOW#1 has the minimum treated wastewater during hydraulic fracturing processes. It corresponds to the large volume of solid and oil particles, which remained in the treatment devices. However, it is observed that SOW#1 has the highest rate of treatment (32%) and SOW#4 has the minimum treated wastewater (14%) in chemical enhanced oil recovery methods. On the other hand, SOW#3 has the highest rate of treatment (27%) and SOW#5 has the minimum treated wastewater from drilling mud preparation and other well facilities. It is observed that SOW#1 has the highest rate of treatment (27%) and SOW#5 has the minimum saving water during hydraulic fracturing processes, SOW#1 has the highest rate of treatment (38%) and SOW#4 has the minimum saving water (9%).

CFD modelling of the flow of ice slurry in a vertical slit channel

In this article, the Euler-Euler method was applied to CFD modelling of adiabatic ice slurry flow, for different flow directions in a vertical slit channel. The mean relative accuracy of determining pressure drops compared to experimental studies was 5.6%. Calculations showed that the relative slip velocity and the effect of flow direction on slip velocity increase with decreasing carrier fluid concentration, decreasing mean flow velocity, and decreasing mean solid particles volume fraction. The mean particle slip velocity does not exceed 4%, and local slip velocity values can be 58% of the mean suspended solids flow velocity. For heterogeneous flow, the highest slip velocities occur at a distance of 15% of the channel width from the channel sidewalls. The shape of the solid particles distribution profile is determined by the mean flow velocity and the mean solid particles volume fraction. Excluding the area at a distance of 8% of the channel width from the sidewall where local maximum (for low velocities) and minimum (for higher velocities) values may occur, the profile is stabilised in the central part of the channel. In this study, the boundary curves between heterogeneous and homogeneous flow were determined for ice slurry flow in a vertical slit channel.

Experimental and theoretical studies on the operating parameters of hydromechanical drilling

Purpose. To analyse certain complex components of the rock breaking act during the well construction stipulated by the design features of the technical means of hydromechanical drilling and diversity of manifestations of hydraulic and physicochemical properties of the activated circulation medium. Methodology. Physicochemical parameters of the process of active substance adsorption from the water solutions on the rock surfaces were studied in terms of their disperse material by identifying optimal ratio in the solid phase particles volume of the activated solution group with the recording of time interval of the adsorption equilibrium establishment. Features of bottomhole processes in terms of the operating modernized facilities of hydromechanical drilling were considered involving up-to-date methods of analytical analysis and experimental-laboratory studies, i.e. by using certain techniques of mathematical and physical modelling, methods for processing and interpretation of the research results by means of SolidWorks, STATGRAPHICS, D, and control-and-measuring equipment and materials. Findings. The peculiarities of the combined hydromechanical drilling technique have been analysed from the viewpoint of the creation of the most efficient conditions of bottomhole rock breaking. Since a considerable degree of the development of breaking processes is the practically proved factor of hydromechanical drilling, the rationalization and intensification of those processes may be achieved by means of controlled physicochemical effect of the surface active medium. The experimental study was carried out to analyse the directedness of the development and results of surface interaction adsorption within the boundary of phase separation as the main factor of intensification of the rock mass breaking. A comparative analysis was performed concerning the surface activity of the corresponding substances that differ in their schemes of dissociation in a water solution whose properties are to be corrected additionally to make them close to the ones peculiar for natural drill muds. Positive influence of the adsorption phenomenon on the results of contact interaction of breaking elements of hydromechanical facilities was examined; this phenomenon is shown in the decelerated wear of metal surfaces. Originality. Useful influence of the physicochemical properties of the substances under consideration decreases beginning from the ionogenic anion-active sulfonol towards the ionogenic cation-active katapin K and to the non-ionogenic substance OP-10 (-10). However, in terms of combining the compositions of the mentioned substances, it can be strengthened additionally. Practical value. The indicated laboratory and experimental studies are the basic ones to design the mode parameters of the washing programme for a hydromechanical drilling well; they belong to the main output data used while substantiating the design and technical-technological parameters of the modernized pellet impact devices.

NUMERICAL AND EXPERIMENTAL INVESTIGATION OF A DOUBLE-PIPE HEAT EXCHANGER WITH SiO2 NANO-ADDITIVES

In this work, numerical and experimental analyses of a double-pipe heat exchanger with SiO2 nanoparticles were performed. The numerical study was conducted by using the k-e turbulence model with the Galerkin weighted residual finite element method. The nanofluid was used in the inner pipe at various solid particle volume fractions. Effects of flow rate and temperature on the overall heat transfer coefficient were examined. The Brownian motion effect was included in the effective thermal conductivity of the nanofluid. It was observed that the overall heat transfer coefficient enhanced with the inclusion of nanoparticle and increasing the volumetric flow rate of nanofluid. Even though the validation of the experimental study was conducted, there are discrepancies between the numerical and experimental studies which become higher for a higher mass flow rate. The deviations are 4.60% and 27.50% at volumetric flow rates of 0.87 L/min and 2.15 L/min.

Numerical study of geometric parameters effects on the suspended solid particles in the oil transmission pipelines

The innovation of this paper is geometric parameters effects of the oil transmission pipelines on the suspended solid particles. This geometry has been simulated with the Lattice Boltzmann Method based on D2Q9 model for analyzing solid particle tracing, streamlines, solid particle volume fraction, and nondimensional velocity field of fluid flow. These parameters have been investigated in 9 cases of the oil transmission pipelines at two different intensity of fluid flow. The results signified that maximum and minimum ranges of fluid velocity at [Formula: see text] were in case 3 that the oil transmission pipelines with diameter of the pipeline and bending radius, D and 2D, respectively. Also, maximum volume fraction of solid particles at bending radius at [Formula: see text] was in case 3 with diameter of the pipeline and bending radius, D and 2D, respectively. Also, in case 9, solid particles in the oil transmission pipelines were almost symmetrical. Finally, with comparison between figures of solid particles tracing and volume fraction of solid particles, by increasing of the diameter of oil transmission pipelines, the sediment of solid particles was decreased, also, by increasing of the bending radius of oil transmission pipelines, the sediment of solid particles was increased.

Numerical Prediction of Erosion Based on the Solid-Liquid Two-Phase Flow in a Double-Suction Centrifugal Pump

Due to the high sediment content in the Yellow River, the pump units in the pumping stations along the line are often eroded by sediment, causing the reduction of pump efficiency and structural damage. The purpose of this paper is to study the influence of particle diameter on the particle track, erosion distribution and erosion rate in a double-suction centrifugal pump in a pumping station of the Yellow River with a Lagrangian particle-tracking approach and a Tabakoff erosion model. The results show that the surface erosion of the impeller on both sides in the double-suction centrifugal pump has an asymmetric distribution, and the erosion rate on both sides is different. The particle diameter affects the moving trajectory of particles and has a significant effect on the erosion morphology and position in the impeller. With the increase of particle diameter, the velocity of the particles moving towards the pressure side of the blade inlet increases, resulting in punctate impact erosion. When the particle diameter decreases, sliding abrasion gradually forms on the pressure side of the blade outlet. The change rule of the solid particle volume fraction on the impeller wall is consistent with that of erosion distribution on the impeller wall. The larger the solid volume fraction is, the higher the wall erosion rate is.

Jet Impingement Heat Transfer of Confined Single and Double Jets with Non-Newtonian Power Law Nanofluid under the Inclined Magnetic Field Effects for a Partly Curved Heated Wall

Single and double impinging jets heat transfer of non-Newtonian power law nanofluid on a partly curved surface under the inclined magnetic field effects is analyzed with finite element method. The numerical work is performed for various values of Reynolds number (Re, between 100 and 300), Hartmann number (Ha, between 0 and 10), magnetic field inclination (γ, between 0 and 90), curved wall aspect ratio (AR, between 01. and 1.2), power law index (n, between 0.8 and 1.2), nanoparticle volume fraction (ϕ, between 0 and 0.04) and particle size in nm (dp, between 20 and 80). The amount of rise in average Nusselt (Nu) number with Re number depends upon the power law index while the discrepancy between the Newtonian fluid case becomes higher with higher values of power law indices. As compared to case with n = 1, discrepancy in the average Nu number are obtained as −38% and 71.5% for cases with n = 0.8 and n = 1.2. The magnetic field strength and inclination can be used to control the size and number or vortices. As magnetic field is imposed at the higher strength, the average Nu reduces by about 26.6% and 7.5% for single and double jets with n greater than 1 while it increases by about 4.78% and 12.58% with n less than 1. The inclination of magnetic field also plays an important role on the amount of enhancement in the average Nu number for different n values. The aspect ratio of the curved wall affects the flow field slightly while the average Nu variation becomes 5%. Average Nu number increases with higher solid particle volume fraction and with smaller particle size. At the highest particle size, it is increased by about 14%. There is 7% variation in the average Nu number when cases with lowest and highest particle size are compared. Finally, convective heat transfer performance modeling with four inputs and one output is successfully obtained by using Adaptive Neuro-Fuzzy Interface System (ANFIS) which provides fast and accurate prediction results.