Abstract:

With the abrasive flow temperature increasing, the viscosity of fluid will decrease in a solid-liquid two phase softness abrasive flow precision machining, leading to the uneven distribution of the turbulent kinetic energy and the dynamic pressure. For this problem, the paper put forward a new machining method, through changing the flow velocity to compensate the influences of the temperature changing on turbulent kinetic energy and dynamic pressure. Based on studying the machining mechanism, the paper considered the turbulent kinetic energy and the dynamic pressure affected the machining texture and material removal rate of the machining surface respectively, then it confirmed a standard of appraising turbulent flow form. Contrasting the size distribution of turbulent kinetic energy and dynamic pressure in the same speed and different temperatures, the influences of temperature on turbulent kinetic energy and dynamic pressure were studied. Contrasting the size distribution of turbulent kinetic energy and dynamic pressure in the same temperature and different speeds, the influences of the speed on turbulent kinetic energy and dynamic pressure were also studied. Through a large number of simulations, it gives the optimal temperature from the nine different temperatures and t-v curve, it offers the reference for the design of turbulent regulation and automatic control system. The experimental results indicate the machining homogeneous degree of workpiece surface has obvious promotion after speed regulation.

Key words: turbulent kinetic energy, dynamic pressure, temperature, parameter optimization

摘要：

针对固-液两相软性磨粒流加工中随着磨粒流温度的升高而导致流体黏度下降，进而导致湍动能和动压力分布不均匀的问题，提出一种新型的加工方法，即通过改变流速来补偿温度变化对湍动能和动压力的影响。基于对加工机理的研究，认为湍动能和动压力分别影响加工表面的加工纹理和材料去除率，确定了一种评价湍流形态的标准。对同一速度下不同温度时的湍动能和动压力的大小分布进行对比，研究了温度对湍动能和动压力大小和分布的影响;对同一温度下不同速度时的湍动能和动压力的大小分布进行对比，研究了速度对湍动能和动压力大小和分布的影响。通过大量仿真求得了9个不同温度下的最优温度，并作出了温度-速度曲线，为以后的湍流调控和自动控制系统的设计提供参考。实验结果表明，调速后工件表面的加工均匀度有明显的提升。

关键词: 湍动能, 动压力, 温度, 参数优化