射流冷却超薄玻璃的数值模拟研究

摘要

采用计算流体力学软件 FLUENT并结合热流固耦合有限元体积方法，通过求解三维 N-S方程和能量方程，对雷诺数Re 为30000~70000和射流间距H 为1~6 mm的圆形孔口，复合型孔口和花型孔口冲击射流急冷超薄玻璃物理钢化过程进行了数值模拟，意在探究单孔射流时超薄玻璃急冷过程的流场分布和换热情况，为实现超薄玻璃表面换热更快、更均匀提供参考依据，从而研发厚度小于2 mm的超薄玻璃物理钢化技术。研究发现：圆形孔，复合型孔和花型孔冲击玻璃表面时在径向射流横截面上出现2个反向漩涡流，分析认为是射流卷吸作用加强并引起边界层发生分离现象，气流向上端扩散从而产生了漩涡流；从被冲击玻璃表面的局部努赛尔系数分布可以看出，采用花型孔口和复合型孔口射流冲击可以使玻璃表面的冲击区域更大，冷却效果更均匀。%In this paper computational fluid dynamics software FLUENT and heat finite element coupling volume method were used,by calculating the three-dimensional N-S equation and energy equation,the simulation of the round orifice,complex orifice and flower type orifice impingement ultra-thin glass tem-pered physical processes was conducted in order to explores the flow field distribution and heat transfer distribution of single-hole quenching ultra-thin glass process,and to provide some basis of achieving faster and more uniform heat exchanging,so that the ultra-thin glass,whose thickness is less than 2mm and physical toughened technology could be developed.The study showed that there are two opposite vortex flow on the glass surface of radical cross section,when round hole,combined hole and flower type hole im-pact the ultra-thin glass surface.The analysis showed that entrainment effect is strengthened and cause boundary layer separation,resulting in airflow spread to the upper end of the swirl flow.It can be seen from the distribution of local Nusselt coefficient on the glass surface that using flower type hole and com-bined hole impinging j et can make a greater impacting area and more uniform cooling effect.