Study on Different Parameters of the Self-Excited Oscillation Nozzle for Cavitation Effect under Multiphase Mixed Transport Conditions

Abstract

The pollution problems of water resources have affected the ecology of the Earth, especially the ecological environment of the oceans. In order to find a cheaper and cleaner organic wastewater treatment method and explore the effect of geometrical parameters and external parameters of self-excited oscillation on cavitation performance, apply it in engineering stably and efficiently, this study took the cavitation effect of self-excited oscillating cavitation jet nozzle as the research target and simulated the geometrical parameters and external parameters of the nozzle. The primary and secondary relationship of the effect of all parameters on cavitation performance was summarized by analyzing the correlation and partial correlation of each parameter. Subsequently, principal component analysis (PCA) was conducted to build a mathematical model of self-excited oscillating cavitation jet nozzle suitable for multiphase transport. As revealed from the results, the contribution rate of parameters to vapor volume fraction followed the order of CLD > d1 > Cd21 > CDd2 > Pin. The ratio of outlet diameter to inlet diameter (Cd21) of the self-excited oscillating cavitation jet nozzle significantly impacted the volume fraction of cavitation vapor (VOF) due to the change of particle diameter, while the influence of other design parameters on VOF was not significant with the change of particle diameter. The larger the content of solid particles, the less the VOF would be impacted by the design parameters. Under the solid particle content of 10% and the particle diameter of 0.2 mm, an independent working point was obtained. In addition, after experimental verification, it was found that the slope of experimental fitting was basically the identical to the corresponding coefficient of parameters in the model. This model and the self-excited nozzle with good cavitation performance provide a theoretical basis for solving the problem of water pollution.

Keywords

• water pollution
• cavitation jet
• self-excited oscillation
• design optimization
• mathematical model