Papers by Keyword: Particle Concentration

Abstract: This scientific study presents experimental results of particle agglomeration and dispersing processes under various physicochemical conditions, focusing on the effects of temperature, particle concentration, and medium viscosity. Using numerical approaches and experimental data, patterns describing the changes in agglomeration rate and the features of dispersing system stability were identified. The key findings of the research include: the influence of temperature on agglomeration, high particle concentration, medium viscosity, dispersion under low particle concentration conditions. It is noteworthy that the results also confirm an exponential dependence of the agglomeration rate on temperature. However, at high particle concentrations, this effect is mitigated by the dominance of interparticle interactions, such as Van der Waals forces and electrostatic effects. Furthermore, in systems with low particle concentration and elevated temperature, agglomeration processes significantly slow down, indicating improved dispersing stability. The study opens new perspectives for controlling particle agglomeration and dispersing based on temperature, concentration, and the physical properties of the medium. The obtained data can be useful for improving existing technologies and developing new ones in areas where controlling the behavior of dispersed systems is essential.

Abstract: Silver nano-colloids have been generated via Laser Ablation Synthesis in Solution (LASiS) system. Nanoparticle formation with particle size below 50 nm in DI water was confirmed using UV-VIS spectroscopy, Dynamic Light Scattering (DLS) technique, and transmission electron microscopy (TEM). Supercapacitor structure, having dimension 11 mm x 10 mm, was successfully Aerosol Jet printed on an untreated polymer substrate using as produced LASiS silver nano-colloid.

Abstract: Swirling Fluidized Bed Polishing (SFBP) is a non–traditional alternative abrasive flow surface finishing form of Fluidized Bed Machining (FBM) in which the former has special features to overcome certain significant limitations of the latter, namely the variation of the surface roughness vertically along the component surface and the screening effect owing to the complex contours in the work piece geometry. Owing to its ability to perform machining and generate polished surface from a roughness value of Ra 1.2μ to 0.2 μ within 8 hours of processing, this new method offers greater scope in the surface modification of rough machined surfaces with complex geometry such as component with ducts and grooves. This research focus on investigating the effect of abrasive particle concentration on metal removal rate per unit area of the specimen surface. 3D surface morphology analysis investigates the quality of the polished surface and the study of circumferential uniformity and machining accuracy analysis on a complex-contoured component further investigate its scope and relevance in industrial applications.

Abstract: In this paper, the effect on the thermal efficiency enhancement of a heat pipe using SiO₂-water nanofluid on different operating states was investigated. SiO₂-water nanofluids with mass concentrations of 0.1% ~ 2.0% have been prepared with the average size of 10nm, 30nm, 50nm, 70nm, respectively. Heat transfer characteristics of the heat pipe including wall temperature distribution, heat transfer coefficient and thermal resistance have been investigated, which showed excellent properties.

Abstract: The complex gas-solid two-phase flow in a full-sized solid rocket motor with embedded nozzle under different acceleration condition was simulated with Euler-Lagrange model. Influences of different particle diameters and acceleration conditions on particle trajectories were analyzed. Simulation results show that the difference between gas flow field and two-phase flow field is significant. The particle accumulation zone above inner wall of chamber and nozzle is mainly concentrated in two regions. The accretion of the particle diameter will cause the following property worse, and the particles can easily form a highly-concentrated aggregation flow. With the increasing of axial-acceleration, the impact point in line2 will move backward in rear head.

Abstract: For two conditions of (non-) vegetation cover in uranium tailings beach face, the concentration distribution and settlement regularity of tailing sand with diameter of 10μm at speed of 0.5, 1, 2, and 4 m/s was studied by numerical simulation method. Results shows, with the increase of wind speed and migration distance, particle concentration decreases. Compared with the non-vegetation cover condition, particles concentration in the condition of with vegetation cover is significantly higher than the condition that without vegetation cover; but along with the increase of horizontal distance, the concentration lowers than the latter gradually.

Abstract: The two-dimension axisymmetric and two-phase flow in a full-size solid rocket motor with submerged nozzle under high acceleration condition has been simulated with Euler-Lagrange model. Without acceleration and under high axial acceleration on particle trajectories, the influences of different particle diameters were analyzed. The difference between gas flow field and two-phase flow field is significant. The particle accumulation zone above the inner wall of chamber and nozzle is mainly concentrated in two regions. The axial acceleration will intensify the impaction to the end of the chamber. The accretion of the particle phase diameter will increase the inertia of the particle phase, which may cause the following property worse, and the particles can easily form a highly-concentrated aggregation flow.

Abstract: The particle concentration and convection velocity profile has been obtained by the adaptation of the random surface renewal model to the particle continuity and momentum equations of the nonisothermal turbulence boundary-layer flows In general, the investigations of particle deposition mainly include incompressible fluid laden by spherical and dilute particles in the fully developed turbulence boundary layer flows. This means that the fluid motion is unaffected by the presence of the particles and that the collisions between particles can be neglected. the relative quiescent viscous sublayer, resulting in the increase in thermophoretic deposition with increased Prandtl number.

Abstract: Based on the discrete phase model (DPM), this paper studies the concentration distribution and settlement regularity of particles which sizes are 10μm and 100μm under the wind speed of 0.5, 1, 2, and 4m/s with the method of numerical simulation. The simulation results show that the particle concentration of 10μm at the downwind direction of tailing is constantly decreasing with the increase of wind speed and migration distance, and the particle concentration of 100μm is gradually increasing, as well as the local pollution also become gradually worse. As wind speed is 0.5m/s, the local concentration of 10μm particles at the beach face of uranium tailings impoundment is higher, and there is much deposition within 2000m of the downwind direction. While the dust emission rate of 100μm is less and its concentration is lower.10μm particles are taken away by the wind, and its concentration would fall rapidly with wind speed increased to 4.0m/s. The concentration of 100μm particle would increase and local pollution becomes more serious.

Abstract: Transmission fluctuation spectrometry (TFS) is a new method for particle analysis based on the statistical fluctuations of a transmission signal. With simple optical arrangement and easy operation, the method can be applied to real-time, online measurements. The transmission signal with fluctuations are analyzed by using 1st order band-pass filters, and the experimental data in the frequency domain are obtained. The particle size distribution (PSD) and particle concentration are extracted from the experimental data with the modifed Chahine interations. It is found that the measurements using band-pass filters are of better resolution in the PSD than those with low-pass filters.