Abstract: The contact time of glass melt and mold is very short in glass blow forming process in which there is a rapid and intensive heat exchange,and the temperature of contact surface changes significantly.Glass viscosity governing glass flow during the forming process is strongly dependent on temperature.A small temperature variation in glass melt may produce a great change in its viscosity,which further affects the distribution of final product thickness.Therefore a coupling simulation of melt and mold heat transfer is crucial.An interface element was developed to deal with heat transfer between glass melt and mold in the glass forming process.The governing equations of melt flow and heat transfer based on the principles of conservation of mass,momentum and energy were expressed in the Lagrangian method.The finite element formulations to solve velocity,pressure and temperature were derived by means of the Galerkin method,and the corresponding program with VC++ was developed.Temperature distributions were calculated from both coupling and iteration methods.The coupling method could give very good result,but the iteration method could not meet the accuracy requirement.The temperature in most parts of the mold kept stable during continuous production except for the area close to contact surface where temperature had high periodic changes.The simulation result was compared with the real industry product.The prediction of thickness distribution was consistent with the real part.The accuracy was more than 88%.

Key words: blow processing, glass forming, numerical simulation, coupling heat transfer

摘要： 玻璃吹制成型过程中熔体与模具接触时间短,热交换迅速、剧烈,同时玻璃的黏度对温度极其敏感,微小的温度波动将会引起黏度的剧烈改变,并最终决定制品的厚度分布,因此熔体与模具传热的耦合求解是十分必要的。鉴于此,本文在熔体与模具接触面上引入了界面单元来处理接触面热阻区的热传递问题,建立了熔体流动与模具温度场耦合模拟的控制方程,完成了算法编制,实现了熔体流动与模具温度场的耦合模拟。算例证明,与耦合传热算法相比迭代结果不足以满足吹制成型对温度场准确性的要求;通过模拟与实验对比,在连续生产条件下模具绝大部分的温度保持稳定,但与熔体接触的型腔壁的温度却有大幅的周期性变化;模拟的最终产品壁厚较准确地反映了产品的实际壁厚分布,准确度达到88%以上。

关键词: 吹制成型, 玻璃成型, 数值模拟, 热耦合