Simulation Of Bubble Growth And Visualiazation Experimental Platform

Recently, because of its superior performance it has been widely used in all fields of society. As one of the most important part in foam processing, bubble growth plays a decisive role in the final of the structure and properties of products. Bubble growth is a very complicated process, which has many influencing factors. It is important for controlling bubble growth and improving the structure and performance of products to analysis the main menchanism of bubble growth and to study the different parameters on the influence of bubble growth.This paper uses cell model as the physical model, and deduces three kinds of bubble growth mathematical model which based on three kinds of different constitutive equation(Newtonian fluid constitutive equations, power-law fluid constitutive equation and Dewitt viscoelastic constitutive equation). After comparing the computer simulation of these three models with the previous experimental data, it is found that Dewitt model has more similar situation with the real bubble growth than power-law model, and the result simulated by Newtonian model has the largest difference with experiment result. Bubble growth mechanism includes momentum transfer and quality transfer. Momentum transfer mainly exists in the beginning of bubble growth and quality transfer exists in the whole process of bubble growth. It is found that temperature, initial system pressure, diffusion coefficient, Henry constants and polymer elastic will promote the growth of bubble, while polymer melt viscosity and surface tension will prevent it.This paper also uses computer to simulate the bubble growth process in PS/CO2 and PP/CO2 system. It is found that temperature has little influence for foaming in PS/CO2 system, while in PP/CO2 system temperature plays a very important role in foaming. Under the same temperature, the bubbles in PP/CO2 system grow much faster than that in PS/CO2 system, and the final bubble radius simulated by computer in PP/CO2 system is also bigger than that in PS/CO2 system.In addition, this paper introduce the process of building the visualization experimental platform for intermittent foaming, including the design of high pressure reaction system, control system and visualization system and the installation and commissioning of platform.