结构化流道环境下不同颗粒浓度的磨粒群分布及其动力学特性

结构化表面流道内,由于流体相的驱动作用,磨粒与磨粒之间、磨粒与壁面之间产生相互碰撞,从而壁面不断受到冲击力和摩擦力而发生磨损。该文基于液-固两相流体耦合理论,利用欧拉-欧拉多相流模型中的mixture模型和Realizablek-ε湍流模型对V型纹理半环形截面流道内液-固两相流在不同颗粒浓度下运行时的壁面湍流效应进行了数值模拟,计算了流场中湍流速度及湍动性能等参数。模拟结果表明:V型纹理的流道有利于涡流的产生,因此可以通过配置V型纹理的约束模块来提高湍流的紊乱程度;随着颗粒浓度的增大,在一定范围内磨粒流的速度逐渐增大,磨粒流的湍动能逐渐减小,磨粒体积分数的波动振幅越来越小;颗粒浓度的选择应适当,不同的颗粒浓度可以产生不同的磨粒流综合性能和颗粒分布效果。

Distribution and dynamic characteristic of particle group with different concentration in structural flow passage

Because of the driving action of liquid phase, particles will be collided the surface and impacted with each other in the flow passage, then the surface will be machined though this continuous action of impact force and friction force. Based on the coupled theory of liquid-solid two phases flow, mixture model which belongs to Euler-Euler multiphase flow model and realizable k-ε turbulence model were used to analyze turbulent effects of liquid-solid two-phase flow in the wall area, and some parameters such as turbulent velocity and turbulent energy were calculated with different particles concentration in the flow passage which had V-shaped texture and semicircular cross-section. Simulation results showed that 1) turbulence could be improved by assembling V-shaped constrained component; 2) as the concentration of particles increased, particles velocity would be increased in a certain range, turbulent energy reduced gradually, and amplitude of particles volume fraction is also decreased; and 3) the concentration of particles should be selected properly and different particles distribution and finishing performance would be obtained with different particles concentration.