Abstract: A two － dimensional axisymmetric model of friction hydro pillar processing （FHPP） was established base on
Gambit software ．Using the commercial computational fluid dynamics software Fluent ， the numerical simulation of plastic
metal flow pattern was carried out in steady phase of FHPP ．While keeping the other parameters constantly during the process
of numerical simulation ，the velocity field and static pressure field distribution change of ideal metal plastic fluid during the
forming process were analyzed by changing only one critical parameter respectively ，such as the radial clearance between metal
stud and the base hole ，the material viscosity ，the rotary speed of metal stud ，the feed rate of metal stud and the bottom shape
of the base hole ．The result show that the static pressure distribution of plastic metal is affected remarkably by the feed rate （i ．
e ．the axial force） and the material viscosity of metal stud ，and has little to do with the rotary speed and the radial clearance ．
Although the feed rate and the radial clearance have little influence on the velocity distribution of plastic metal ，the effect of
rotary speed is relatively remarkable ，especially for the material neighboring to the wall of the velocity inlet and nearby the
metal stud ．The flow condition of the plastic metal material can be improved by changing the bottom shape of the base hole ，
which can also reveal the reason why there exist some defects at the bottom of the hole ．The above － mentioned research can
provide some guidance to the future experimental study adopting appropriate parametric combination ，and can also lay solid
foundation for the future numerical simulation by thermo － mechanical coupling ．

Key words: Friction hydro pillar processing （FHPP） , Friction stitch welding , Computational fluid dynamics , Numerical simulation

摘要： 采用 Gambit软件建立了摩擦液柱成形(FHPP)过程流场的二维轴对称模型,运用商业计算流体动力学软件 Fluent对 FHPP稳态阶段塑性金属的流动情况进行了数值模拟。通过改变模拟过程中的单一关键参数而保持其他参数不变,分别讨论了金属棒和孔洞之间径向间隙、材料粘度、金属棒转速、金属棒进给速度以及基材孔底形状等对理想金属塑性流体流动成形过程中速度场和压力场分布变化的影响。结果发现,塑性金属材料的压力分布主要受进给速度(即轴向力)和材料粘度的影响,与金属棒的旋转速度和径向间隙关系不大;而速度分布受进给速度以及径向间隙的影响不明显,但与金属棒的旋转速度关系密切,尤其是靠近速度入口面以及金属棒附近的材料受旋转作用影响显著;通过改变基材孔洞底部的形状,可以改善塑性金属材料的流动情况,同时也揭示了实验过程中孔洞底部存在缺陷的原因。

关键词: 摩擦液柱成形 , 摩擦叠焊 , 计算流体动力学 , 数值模拟