固体推进剂药浆收缩流动数值模拟与实验验证

Numerical Simulation and Experiment of Solid Propellant 4∶1 Contraction Flow

利用Phan Thien-Tanner(PTT)黏弹本构模型,通过CFD黏弹性流体软件Ansys-Polyflow对固体推进剂药浆4∶1收缩流进行数值仿真模拟,研究了固体推进剂药浆在不同松弛时间,流道收缩口处的等值线流体形态、流动速度、法向应力效应等特性。研究表明,随着松弛时间延长,流体的韦森堡效应逐渐增大,在收缩流道入口的角落处产生涡流或二次流现象越明显;在收缩流道入口处,由于流动面积减小,为保证流体质量守恒,流体沿着中心轴流动方向加速,且速度梯度方向与流体的流动方向一致,即中心轴处产生了大应变速率的拉伸流动,远离中心轴靠近壁面处流动以剪切流动为主。

The Phan Thien-Tanner(PTT)viscoelastic constitutive model was used to simulate the solid propellant 4∶1 contraction flow by CFD viscoelastic fluid software Ansys-Polyflow.The fluid streamline form,flow velocity and normal stress effect of the solid propellant slurry at the contraction port of the channel were studied under different relaxation time.Studies have shown that as the relaxation time increases,the Weissenberg effect of the fluid gradually increases,and the phenomenon of eddy currents at the corner of the contraction port is more obvious.At the entrance of the contraction channel,as the flow area is reduced,the fluid accelerates along the direction of the central axis to ensure fluid quality conservation,and the velocity gradient direction is consistent with the flow direction of the fluid at the central axis,where an extensional flow with a large strain rate is generated.The flow away from the central axis and near the wall is dominated by shear flow.