In certain industries, such as the Chinese pharmaceutical pill preparation medicines, the occurrence of satellite droplets and the inconsistent diameters of the main droplets lead to wasted resources and affect the normal operation of the production system. So it is necessary to investigate the formation process of main droplets and the elimination method of satellite droplets in the jet process. In this paper, the effects of the liquid level height, dropper inner diameter, and glycerin mass fraction on the formation of the droplets are revealed, and the optimal frequency for eliminating satellite droplets is explored. The results show that the diameter of the main droplets increases as the liquid level height and the dropper inner diameter increase and decreases as the glycerin mass fraction increases. The fracture length has a growing trend as the liquid level, dropper inner diameter, and glycerin mass fraction increase. With the increase in the dropper inner diameter and glycerin mass fraction, the generation period increases. However, the increase in the liquid level height has an opposite influence on the other parameters. The optimal frequency for eliminating satellite droplets increases as the liquid level height and dropper inner diameter increase and decreases as the liquid becomes more viscous. However, the diameter and generation period of the main droplets decrease when a longitudinal disturbance is added to the jet system.

The thermal effect of the viscous oil film of hydrostatic bearings is the key factor causing bearing errors, and the hydrostatic bearing working surface with microgroove structures can potentially inhibit the thermal effect and effectively ensure the bearing accuracy. In this study, a modeling method for oil film heat generation of hydrostatic bearings with a rectangular microgroove working surface is established, and the influence of microgroove design scales onto oil film heat generation is studied. First, the flowing field numerical simulation model of the hydrostatic bearing oil film is established and verified by the published analytical model. Based on the simulation method, oil film flowing behaviors of hydrostatic bearings with a rectangular microgroove working surface are studied. Then, by combining the analytical calculation of viscous heat generation of the hydrostatic oil film and its flowing field simulation, a modified oil film thermal modeling of hydrostatic bearings with the rectangular microgroove working surface is established. On this basis, the influence of the microgroove design scale onto oil film heat generation is studied. It can be concluded that with the appropriate scales of the rectangular microgroove, the working surface with microgrooves can reduce the average velocity of the viscous flow field of the hydrostatic bearing oil film and restrain its energy loss and heat generation.

In this paper, the atomization characteristics of an effervescent atomizer were investigated. The velocity, Sauter Mean Diameter (SMD) and atomization cone angle of the droplets were measured using the Phase Doppler Analyzer (PDA) to discuss the effect of different design parameters. The results showed that the atomization was unstable at a small Gas-Liquid Rate (GLR) while the atomization proved gradually by increasing the GLR. The optimal atomization region was at a GLR=0.1. In the atomization process, there existed a typical velocity distribution for the swirl atomizer. The design parameters of atomizer provided a great influence on the Sauter Mean Diameter (SMD) and atomization cone angle. The experiment results showed that some droplets had negative velocities.

Effervescent atomization is widely used in industrial, agricultural, and national defense fields because of its low energy consumption. Quality improvement to spray has been pursued for decades as an important goal without increasing energy consumption. To investigate the relationship between the internal flow and spray characteristic, a swirl effervescent atomizer coupled with a wire mesh was designed in this paper. The effect of wire mesh on spray characteristics and internal flow with different structural parameters was investigated. The experimental results showed that the spray quality (small droplet diameter and stable atomization) was improved by installing a wire mesh in the mixing chamber. The droplet diameter decreased first and then increased with the increase in the effective porosity of the wire mesh, and Sauter mean diameter decreased from 23.1 to 20 μm. Moreover, this study adopts the simulation to explore the influence of bubble size on the spray droplet in the mixing chamber. The simulation results showed that as the effective porosity of the wire mesh increases, the proportion of small-scale bubbles (the bubble diameter Db ≤ 1 mm) increased from 11.3% to 83.37%, resulting in reduced spray droplet diameter. Notably, the number of small-scale bubbles increases first and then decreases, and the mean pressure drops decline.