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An experimental device for testing droplet evaporation under the action of ionic wind was designed. The dynamic evaporation behaviors of evaporation rate, oscillation amplitude and oscillation frequency of deionized water droplet under different electric fields and ambient gases were investigated, and the velocity distribution of ion wind field was also measured. The results show that when the voltage is lower than the corona voltage, the electric field force can reduce the droplet evaporation rate. When the voltage is higher than the corona voltage, the formation of ion wind can strengthen the droplet evaporation. Both of the increases in voltage and gas ions mobility can augment the ionic wind speed, which intensifies the droplet oscillation and increases the droplet evaporation rate. Compared with the natural evaporation of droplet, the maximum enhancement ratio of droplet evaporation rate under the action of ion wind can reach 9.89. With the increasing of voltage, the ion wind changes from the unstable status to the stable status. [ABSTRACT FROM AUTHOR]

To optimize the thermal resistance of thermoelectric generator for improving performance, the output performance variation of thermoelectric generator with different thermal resistance at both sides was investigated. The external ceramic substrates with different thermal conductivity and thickness were used to simulate the thermal resistance at both sides of thermoelectric generator. The variation of temperature difference, open-circuit voltage, output power and maximum output power of thermoelectric generator at different hot source temperatures and load resistances was analyzed. The results show that when the thermal resistance at both sides of the thermoelectric generator is the same, the temperature difference and the open-circuit voltage are increased with the increasing of hot source temperature. When the thermal resistance at both sides of thermoelectric generator is different, the open-circuit voltage and the maximum output power are increased with the increasing of hot source temperature. The effective temperature difference is increased with the increasing of load resistance, and the power is increased first with latter decreasing when the load resistance is increased. Compared to the performance of thermoelectric generator with the same thermal resistance at both sides, the ceramic substrate with smaller thermal resistance at the hot side is more beneficial to improve the output performance of thermoelectric generator, and the improvement effect is more obvious near the maximum power point. The open-circuit voltage, the maximum output power and the maximum effective temperature difference can be increased by 0.64 V, 0.87 W and 24.5 ℃, respectively. [ABSTRACT FROM AUTHOR]

To improve the removal efficiency of flue gas fine particles in the desulfurization tower by wet desulfurization technology, a new set of purging electrically charged atomization nozzle device was designed and applied to the visual desulfurization tower model test bed. The effects of operating parameters on the particle removal efficiency were systematically investigated. The results show that the charge effect of spray droplets is greatly affected by spray flow rate and spray angle, and there is an optimal charge effect working condition value. With the increasing of particle size, the overall particle classification removal efficiency is increased. The particle removal efficiency is increased with the increasing of fluid flow rate and decreased with the increasing of flue gas flow rate, which is increased firstly with latter decreasing by increasing the dust concentration. The removal efficiency of particulate matter can be further improved after the droplet is charged, and the purpose of efficient removal of fine particulate matter can be realized. [ABSTRACT FROM AUTHOR]

The high-voltage AC electric field was used to promote the separation of soybean oil-methanol transesterification product biodiesel and glycerin. The effects of electric field strength, alcohol-to-oil molar ratio and catalyst on the sedimentation rate of glycerin droplets were explored, and the physical prope11ies of biodiesel and by-product glycerin prepared under different transesterification conditions were measured. The results show that the high-voltage AC electric field can effectively improve the separation efficiency of biodiesel and glycerin. GC-MS test results show that high-strength electric fields has no effect on the quality of biodiesel. In the electric field formed by spiral electrode, the coalescence efficiency of glycerin reaches the maximum when the electric field strength of E' is 175 V · mm -1. Different molar ratios of alcohol and oil can cause differences in the physical properties of the by-product glycerin and have little effect on the sedimentation rate of glycerin droplets. The increase of alkaline catalyst content can promote the sedimentation of glycerin, and the sedimentation efficiency of glycerin under the action of potassium hydroxide is increased. [ABSTRACT FROM AUTHOR]

To analyze the accuracy and differences of diverse turbulence models in predicting the flow around baffles of self-designed wet dust treatment system, several representative Reynolds Averaged Navier-Stokes (RANS) models of Standard κ-ε, RNG κ-ε, SST κ-ω and RSM were selected to simulate the vortex flow induced by arc baffles respectively, and the simulation result was also compared with experiment data. The simulation parameters mainly include the vortex structure, pressure distribution and velocity distribution, and the results show that all the simulations based on the four turbulence models can roughly describe the main characteristics of the vortex flow around baffles, while the Standard κ-ε and RNG κ-ε modes are more accurate. For the pressure drop and total pressure distribution, the results of Standard κ-ε model deviate from the other models, and the decreasing sequence of predicted values is Standard κ-ε，RNG κ-ε，RSM and SST κ-ω. The predicted results of RNG κ-ε model for longitudinal velocity are the closest to the experiment data, while the accuracy of SST κ-ω model for predicting near wall flow and lateral velocity is relatively high. [ABSTRACT FROM AUTHOR]

To discuss the transition mechanism of electrostatic atomization mode, a visualization research on the characteristics of electrostatic spray of nano-fluid was conducted by microscopic high-speed camera technology. Using nano-fluids with different mass concentrations as experiment medium, the microscopic morphology of eletrosprays was captured to discuss the effects of surface tension, flow rate and conductivity on the evolution of electrostatic atomization of nano-fluid. The experimental results show that with the increasing of mass concentration of nano-fluid, the atomization range of cone-jet mode gradually becomes narrow, and the critical electric field intensity gradually increases for atomization range transition to cone-jet mode. The increasing of conductivity make nano-fluids more likely transform to multi-jet mode. The increasing of flow rate causes the instability of atomization, and the higher electric field intensity should be required to achieve the same atomization effect. [ABSTRACT FROM AUTHOR]

To investigate the flow field characteristics of large-size plant protection unmanned helicopter hedgehopping，the numerical simulations were conducted,and the full-size physical model of the large-size helicopter was established. The three-dimensional flow field of large-size unmanned helicopter hedgehopping was simulated by SST k-ω turbulent flow model. The results show that the downwash flow field is relatively disorder under the fuselage because of the obstruction of fuselage.The distribution characteristics of downwash are generally consistent at the same nozzle location of different height，however the distribution characteristics of downwash are quite different for the same flight altitude at different nozzle location. The vertical velocity is increased with latter decreasing along the direction of rotor at the spray boom location，and the maximum velocity is obtained near the x/R value of 0.8. The width of plant canopy velocity is increased with the decreasing of flying height，and the better fly height of H is 4 m. The boom of UAV should be installed in the area with z from -1.50 to -2.00 m and x from -0.50 to 0.50 m. [ABSTRACT FROM AUTHOR]

Dielectric barrier discharge reaction technology is an effective way to achieve the hydrogenation and upgrading of thermosensitive bio-oil under mild reaction conditions. To analyze the hydrogenation reaction pathway and mechanism of each component of bio-oil under the condition of dielectric barrier discharge, hydrogenation experiments and theoretical investigation on the simulated bio-oil prepared by model compounds were conducted based on the previous studies. The results show that butyric acid and butanol are mainly esterified to produce butyl butyrate, and the hydrogenation liquid product of hydroxyl acetone is mainly isobutyl aldehyde. Furfural is mainly saturated by hydrogenation to produce furfuryl alcohol, and the guaiacol is mainly broken by methyl to produce catechol and further hydrogenation to cyclohexene. The conversion rates of model compounds of butyric acid, butanol, furfural, hydroxyacetone, guaiacol, ethyl acetate and cyclohexane are 82.86%, 85.95%, 82.05%, 83.79%, 51.70%, 68.54% and 13.03%, respectively. Acid, aldehyde and ketone can lead bio-oil to poor corrosion and thermal stability and show high reactivity. [ABSTRACT FROM AUTHOR]

The deionized water was used as discrete phase liquid with biodiesel as continuous phase liquid. According to the interface stress balance, the dispersion equation of discrete phase liquid under the action of needle plate electrode was established, and the characteristics of the interface wave dominating the breakup of discrete phase liquid were analyzed. The micro-high-speed camera technology was used to visualize the interface morphology of charged deionized water in biodiesel to obtain the breakup mode and formation mechanism of the discrete phase liquid. The results show that the breakup modes of deionized water in biodiesel can be divided into drop mode, swing drop mode and cone-swing jet mode. The observation results of the interface wave characteristics in different modes indicate that in the drop mode, only the axisymmetric wave exists on the interface, while in the swing drop mode and the cone-swing jet mode, the axisymmetric wave coexists with the non-axisymmetric wave. With the increasing of charging voltage, the optimal wave number of the axisymmetric wave and the non-axisymmetric wave is increased. The optimal wave number of the axisymmetric wave is larger than that of the non-axisymmetric wave, but its growth rate is slower than that of the non-axisymmetric wave. [ABSTRACT FROM AUTHOR]