Journal of Electrostatics最新文献

Lightning fire is one of the biggest dangers for chemical and petrochemical storage tank farms, particularly in floating roof oil tanks (FROTs). To improve the lightning protection of FROTs, the process of floating roof tanks affected by lightning is analyzed. Lightning inductive effects can result in the undesired operation of the above-ground storage tank equipment and endanger exploitation safety. The time domain finite element analysis based on the transmission line model (TLM) method is regarded as a numerical technique to solve field problems by implementing circuit equivalents. This study aims to analyze lightning strike characteristics using the Heidler current function and simulate electromagnetic field strength (EMFS) distribution and surface current density (SCD). Calculation of minimum possible effective strike distance and shielding effectiveness (SE) is performed. Parametric modeling ensures accurate modeling of the roof's bypass conductor to the shell. By utilizing the Parameter Sweep technique, multiple simulations can be carried out with varying structure parameter values. This approach ensures optimal efficiency and accuracy in the results obtained.

Electrohydrodynamic (EHD) printing has been recognized as a promising additive manufacturing technology with superior pattern resolution and economic viability. The shape of Taylor cone is deemed a pivotal element for the amplification of deposition efficiency, and the maintenance of consistent operational steadiness in EHD printing. The correlations between diverse operating parameters and the shape of Taylor cone are presently not well investigated. In this paper, modeling of relationships between operating parameters and the shape of Taylor cone was conducted with a backpropagation neural network (BPNN) and a genetic algorithm optimized backpropagation (GA-BP) neural network. Taylor cone semi-vertical angle and the meniscus height were employed as two indexes to characterize the shape of Taylor cone. The prediction accuracies of BPNN model and GA-BP model were 92.79 % and 95.46 %, respectively. The GA-BP model demonstrated higher precision in forecasting the shape of Taylor cone. A predictive framework for the shape of Taylor cone was proposed, which provided a practical tool for process optimization in EHD printing.

Molecular dynamics simulations are used to study the mechanisms of droplet electrocoalescence and their importance in understanding the microscopic motion of matter and validating existing theories. This review summarizes recent advancements in the use of molecular dynamics simulations to study droplet electrocoalescence and its influencing factors. The limitations of current research and future directions for further development are discussed. The importance of studying the interactions between different components under the influence of electric fields is highlighted. Suggestions for future investigations are proposed based on the current research status.

In printing applications, microparticles are commonly triboelectrically charged with larger carrier particles. Here, we develop an impaction-differential mobility analyzer-optical particle spectrometer (DMA-OPS) system to examine the size-dependent charge distributions of toner particles in the 0.3 – 10 $\mu m$ range resulting from triboelectric charging via acrylic-coated ferrite carrier. The toner-carrier blend is aerosolized, and toner particles are released from the carrier via inertial impaction of toner-carrier complexes. The toner particles are then classified by electrical mobility and their optical diameters are determined. We can produce toner particle size-dependent charge distributions, which can be converted to surface potentials, and charge-to-mass ratios.

Winter season is the time of increased emission of exhaust gases from household heating appliances containing particulate matter (PM) and other noxious contaminants. Many old buildings and single houses, particularly at rural and small town regions, still use stoves, fireplaces or ovens to flat heating. Besides qualified fuels like coal or biomass pellets, all kinds of wastes are also burned in many cases, producing not only mineral particles but also toxic volatile organic compounds or other carcinogenic species. To solve the problem of high level of emission of solid particles and organic-compound molecules different constructions of electrostatic precipitators, which can remove such particles, have been developed in last two decades, which were designed to operate downstream of small domestic boilers. Such electrostatic precipitator must comply with the ECODESIGN emission limits, which set the emission level at 20 mg/m³, for biomass. The mass collection efficiency should be higher than 95 % to obtain this emission level. This brief review presents different constructions of electrostatic precipitators designed to be used for the removal of fly ash particles from domestic heating appliances.

Using simulations, this study aims to investigate the actual charge distribution and resulting electrostatic potential during the filling process of a grounded metal barrel with low-conductivity diesel fuel. The flow rates used for loading were proposed based on the assumption of uniform charge distribution. Deviating from the uniform charge assumption, we observed local charge concentrations, including on the surface of the liquid. Despite the excessive surface charge, the maximum surface potential closely aligns with the prediction of the uniform charge assumption. This supports the practical viability of the proposed flow rates. Yet, considering a higher safety factor is advisable.

The circuit oscillation generated during the process of pulsed arc electrohydraulic discharge can prolong the discharge time and pose potential hazards to the withstand voltage of the discharge equipment. To enhance the anti-oscillation performance of the equipment, the structure of the gas spark switch was analyzed and an improved pulse power switch for suppressing circuit oscillation was designed. Firstly, a two-dimensional axisymmetric simulation model of the gas spark switch was established by COMSOL software, and a theoretical model to express the impedance of the plasma channel through the series combination of resistance and inductance was put forward. Then, the correctness of the theoretical model was proved by the nonlinear regression method considering the capacitance effect of plasma discharge, and the results show that the theoretical model almost coincides with the actual discharge waveform, with a fitting rate of 99.73%. Finally, a thyristor-based pulse power switch was designed, and an electrohydraulic discharge experiment was carried out. The experimental results show that the designed switch can reliably control the output of the high-voltage pulses even if the repetitive discharge frequency is higher than 60 Hz under 8.5 kV voltage. Furthermore, the circuit oscillation process was suppressed, and the oscillation time was reduced from 242μs to 39 μs, with a decrease of 83.88 %. This study has potential application value in underwater high-voltage discharge applications.

This paper proposes the general design of a Wet Electrostatic Scrubber aimed at mitigating fine and ultrafine particles emissions from domestic heating boilers. The design is based on particle capture modelling supported by specific experiments and technical literature information. Results indicate up to 96.6% removal efficiency, consuming 1.2 kg/h of water and 0.3 W per 1 m³/h of gas treated. Comparative analysis highlights the balanced performance of Wet Electrostatic Scrubber in particle capture, energy and water usage, pressure drop, and space occupancy, with the additional benefit of more efficient absorption of gas pollutants.

The epidemiological information concerning novel corona virus (SARS-Cov-2) seeks attention nowadays to get an overview of global as well as country-based cases and deaths so far. The utilization of face mask has become evident for the protective measure of mankind to filter out the infiltrating virus from outside. In this paper, we have analysed various triboelectric based energy harvester configurations focusing on its application in self-powered smart mask design to combat SARS-Cov-2. Smart mask will comprise of triboelectric nanogenerator (TENG) and a smart layer to execute electrocution of the infiltrating virus as well as ensure the safety of human being (I < 10 mA). The theoretical investigations and simulation studies are carried out for different triboelectric materials and a comparative analysis is also portrayed in the context of designing self-powered smart mask under different operating modes. It has been observed that polypropylene-poly methyl methacrylate (PP-PMMA) material combination produces an electrical field of 0.9916 MV/m which is sufficient to electrocute the virus without causing harm to human body. Hence the design and comprehensive analysis is carried out considering PP-PMMA combination for various possible modes of operation like constant velocity, constant acceleration, sinusoidal and generic one. Here, respiration is considered as major mechanical input source for TENG whereas other biomechanical activities like talking, chewing are also discussed in the context of self-powered application of smart mask. It has been demonstrated that the physiological activity like chewing and respiration altogether produce a typical input force of 23.65 N which is sufficient to electrocute the incoming virus without causing any hazard to human health.

A newly designed voltage treatment chamber for AC electric field application with high voltage transformer, voltage divider, over current limiter, and vacuum treatment chamber was utilized to treat red beetroot samples by 0.00–11.5 kV, 400–1013 mbar, and 18.15–20.00min. Applied processing parameters caused a significant increase in the total antioxidant capacity. The best-fit multiple (non-) linear regression models with response optimization revealed 4.6 kV, 400 mbar, and 30.90% moisture as the most optimal processing parameters with 0.8313 composite desirability. Application of electric fields may be utilized for the electroporation of the plant tissue without adverse effect on important properties.