木塑复合材料挤出成型流场的有限元分析

在不同螺杆转速和模具温度条件下制备木塑复合材料,采用旋转流变仪得到不同加工工艺流变参数。利用Polyflow有限元分析软件模拟分析挤出工艺对挤出成型流场的影响。结果表明,随着螺杆转速的增加,压力场波动变化并明显提高,挤出口模的速度场和剪切速率场均明显提高,黏度场逐渐降低,螺杆转速为20 r/min时压力相对平稳;模具温度对速度场和剪切速率场影响较小,但模具温度越高压力场越小。挤出成型流场的有限元分析结果与试验结果基本吻合。

Numerical Simulation of Integrative Flow Field for Hypersonic Vehicle

To meet the requirements for the aerodynamic performance and thrust force demanded in hypersonic missions, the integration design of fuselage and. engine must be considered for hypersonic vehicle with a scramjet engine. The configuration of wave rider is a typical hypersonic vehicle shape, whose fore-body can compress the flow in advance and provide uniform flow for the air intake, and whose aft-body,is used as an expansion surface of nozzle. In the present paper, an engineering method is applied to define total aerodynamic characteristics of an approximate wave rider configuration. A finite volume method based on the center of grid is also employed to numerically investigate the outflow pass the same configuration. The flow field details and the aerodynamic characteristics at given conditions are obtained. The evaluation for this configuration may be used as a guide for the hypersonic vehicle experiment.