Study On The Principle Of Bubble Oscillation In The Bubble Expanding Process Of Foam Molding

In this dissertation, the bubble oscillation principle in the bubble expanding process of foam molding was studied. The reason of bubble oscillation was explained, the law and characteristic of bubble oscillation was revealed, the influence factors and their action on bubble oscillation was discussed, the influence of bubble oscillation on bubble expanding was analysed, and the methods controlling bubble oscillation were searched. On the one hand, this enriched bubble expanding principle theoretically. On the other hand, actual guidance was provided for the purpose of strictly controlling foam molding, improving foam part quality etc.As gas and liquid phase coexisted in the process of bubble expand, the principal of bubble expand was complex and influence factors more. In the study of seniors, only studying liquid phase of BES or ignoring gas phase was capable of less correctly reflect bubble oscillation behavior in bubble expand process. So liquid phase and gas phase of BES were researched at the same time in order to reveal nature and law of bubble oscillation in bubble expanding process in the dissertation.In mis dissertation, the reasons of bubble oscillation was explained from physical phenomenon. Liquid phase of bubble expanding system(BES) was studied and viscoelastic constitutive equation was introduced so as to gain mathematical model controlling bubble oscillation of liquid phase i.e. bubble expanding equation. By means of linearizing bubble expanding equation, linear approximate analytic solution was received. From the mathematical and physical meaning of the solution, the nature and property of bubble linear oscillation was showed. This provided a criterion validating the correctness and reliability of numerical solutions.The gfs in a bubble was regarded as a independent substantial system in the dissertation when gas phase investigated. Gas thermodynamics theory was applied to studying the transfer phenomenon of gas phase of BES in order to set up conservation equation groups. We adopted perturbation method to handle the equation groups to disperse mathematical solution difficulty, finally educed mathematical model of...