Measurement on Spray Flow Field of Premixed Air-blast Electrostatic Nozzles by Using PIV

In order to achieve a stable charge spray in a high humidity environment, we designed a premixed air-blast electrostatic nozzles and spray system by using the method of air ionization and liquid mist mixing. Particle image velocimetry(PIV) was used to measure the spray flow field of the nozzle at different gas-liquid ratios and different voltages. The velocity and vortices of the spray were analyzed under different conditions. The experimental results show that the maximum velocity of the spray flow field negligibly changes when the ratio of gas to liquid increases, but the high speed area increases in the spray flow field, and extends from the upper part of the flow field to the downstream. With the increase of gas liquid ratio, the turbulence degree of spray flow field is significantly improved, and the spray bundling property is gradually weakened, at the same time, more vortices with small scale and high dispersion are derived. With the increase of voltage, the disturbance degree of the spray flow field increases gradually, and the electric field has little effect on the flow field of the mainstream flow of the charged spray, but the disturbance degree to the edge of the liquid spray is obvious, which makes the streamline to become cluttered and produce more small scale vortices. © 2020, High Voltage Engineering Editorial Department of CEPRI. All right reserved.