结构化表面环境下软磨粒流的流场数值分析

Numerical analysis of soft abrasive flow in structured restraint flow passage

为了研究模具结构化表面环境下软性磨粒流的流场加工特性,应用单颗动力学模型(SPD)通过数值模拟求解了颗粒在不同形态的湍流场中的运动特性。以U形流道为例,利用N-S方程、湍流的Realizable(k-ε)模型以及压力耦合方程的半隐相容(SIMPLEC)算法,求解了软性磨粒两相流场中流体的速度、压力等特性参数;接着利用SPD求解多种环境下软性磨粒两相流场中颗粒的速度、轨迹、密度分布等参数。实验结果表明:在流体初始速度为5,10,20m/s 3种情况下,流体初始速度为5m/s时颗粒沉降最为明显;在颗粒直径为0.01,0.05,0.1mm 3种情况下,直径为0.01mm时颗粒沉降较为明显;在水、柴油、机油3种不同黏度的湍流场中,两相软性磨粒流场特性非常接近。结论显示,流体的初始速度和颗粒的粒径使得湍流对颗粒运动特性影响较大,流体的黏性对其影响较小。

In order to explore machining characteristics of the soft abrasive flow field in a structured mold surface,the Single Dynamics Model（SPD） was applied to the solution to the motion characteristics of particles in different types of turbulence fields numerically.By taking a U-shaped flow passage for an example, the velocity and pressure of fluid in a two-phase soft abrasive flow field were solved by using the N-S equations,a Realizable k-ε model of turbulence and the SIMPLEC method.Then the velocity,locus and the density of particles in the two-phase field were also obtained by the SPD model.The results are that when the initial fluid velocities are 5,10 and 20 m/s,the particle deposition is the largest for the first case.When the particle diameters are 0.01,0.05 and 0.1 mm,the first value causes the particle deposition to be most obvious.In turbulence fields with different viscosities,the water,gas-oil and engine-oil show similar two-phase soft abrasive flow characteristics.It concludes that the initial velocity of the fluid field and the diameters of particles have more severe effect on the moving characteristics of particles,and the viscosity of the fluid influences them the least.