Many-body dissipative particle dynamics analysis: Generation and stability of bulk nanobubbles under the influence of pressure

Bulk nanobubbles can be generated through various methods such as ethanol-water exchange, vacuum method, and pressure method. However, the mechanisms and stability of nanobubble generation under pressure are unknown. In this study, a new pressure control method is proposed by combining the pressure control advantages of dissipative particle dynamics (DPD) with molecular dynamics (MD). The effectiveness and rationality of the new pressure control method are validated by using system temperature and pressure as indicators. Furthermore, based on the Ferralo experiment, the experimental process is decomposed and abstracted into specific simulation processes to investigate the effect of pressure on the stability of bulk nanobubbles. The results show that the pressure changes in the two-phase flow can be well controlled by the pressure plate and the pressure regulator based on DPD. A large amount of bulk nanobubble generation occurs during depressurization in a confined space, while pressurization leads to the dissolution of unstable bulk nanobubbles, while stable bulk nanobubbles persist. © 2024 Elsevier B.V.