不饱和聚酯包覆层流动及浇注的仿真模拟

Flow and Casting Process Simulation of Unsaturated Polyester Coating Layer

固体火箭发动机技术的发展对现有的包覆层生产技术提出了新的挑战,采用热固性树脂作为基体,结合连续自动化包覆技术,可快速得到成型完整、性能优异的包覆层,是近年来较为热门的包覆层生产方法。本研究分析了不饱和聚酯(UPR)包覆层的流动性和浇注条件,通过在Fontana‑Kiuna模型基础上引入指数函数,得到匹配的化学流变模型,建立了UPR固化时粘度与时间、温度的函数关系,得到了适合包覆层浇注操作的温度;以Bird‑Carreau幂律方程建立UPR流体的本构方程,使用Polyflow软件在前述温度下对恒速模式和恒压模式下UPR包覆层的浇注过程进行模拟,分析了浇注速率、浇注压力对充填完整性的影响,预测了包覆层的填充体积分数分布、流动速率分布和熔接线位置。结果表明,为了保证UPR包覆层浇注完整,浇注温度应该在35℃以下,浇注压力应大于1 MPa,入口流速应大于150 mm^(3)·s^(-1)且小于175 mm^(3)·s^(-1)。

The new challenge to the existing coating layer process was put forward by the development of solid rocket motor technology.In recent years,thermosetting resin as the matrix was used,combined with continuous automatic coating technology,the popular coating production method of coating layer lies in whether complete molding and excellent performance can be obtained quickly.The flow properties and casting condition of unsaturated polyester(UPR)coating layer were studied.The chemical rheological model of the UPR coating layer during continuous automatic manufacturing is obtained by introducing exponential function based on Kinua‑Fontana model.The functional relationship of viscosity versus time and temperature of cured UPR is established.The suitable temperature for casting operation was obtained.The filling volume fraction distribution,flow rate distribution and weld line position of coating layer were predicted by introducing of POLYFLOW simulation software,which the constitutive equations is established on the base of Bird‑Carrea power‑law equation.The casting process was simulated at the constant rate and pressure,respectively.The results show that the casting temperature is below 35℃,the casting pressure is more than 1 MPa,and the inlet flow rate is more than 150 mm^(3)·s^(-1) and less than 175 mm^(3)·s^(-1) in the coating layer casting process.