基于软性磨粒流抛光超声波激振湍流强化的初步研究

Preliminary study based on turbulence strengthen of softness abrasive flow precision machining by ultrasonic

在固-液两相软性磨粒流加工方法中固定的约束模块中存在湍动能和动压力的分布不均匀、加工时间偏长、加工效率偏低等问题,为解决以上问题,将超声波激振技术应用于固—液两相软性磨粒流加工中。针对超声波激振在液体中产生的压力场改变,在高幅和高频的交变压力场的激励下,分析了流场产生的周期性空化现象,建立了超声波激振与固—液两相软性磨粒流之间的关系;在软性磨粒流加工方法的基础上,提出了在约束流道中耦合超声波激振的方法,从而达到了扰动流场增强湍流强度的目的;在减少加工时间,提高加工效率和减少能耗上对新提出的方法进行了评价;通过大量的仿真,得到不同时刻约束流道内的压力、速度和湍动能分布图,并与定常流道内的压力、速度和湍动能分布图进行了对比。研究结果表明,超声波激振带来的压力场变化能够实现提高加工效率和加工质量的目的。

In order to solve the problems of the uneven distribution of turbulent kinetic energy and dynamic pressure in the fixed constraint module, as well as the processing time is rather long and low processing efficiency in the solid-liquid two-phase softness abrasive flow precision machining, the ultrasonic technology was investigated in the solid-liquid two-phase soft abrasive flow machining. Aiming at the ultrasonic change of the pressure field in the liquid, as well as in the excitation of high amplitude and high frequency alternating pressure field, the periodic cavitation of the flow field was analyzed. The relationship between the ultrasonic excitation and solid - liquid two-phase soft abrasive flow was established. Based on the soft abrasive flow machining method, a method was presented to coupling the ultrasonic in a constrained flow field, so as to achieve the purpose of the disturbed flow field. The new method was evaluated on the reducing processing time, improving processing efficiency and reducing energy consumption. The figures of pressure, speed and turbulent kinetic energy distribution at different times within the constraint flow channel were gotten through a large number of simulations. The results show that the pressure change in the field generated by the ultrasonic field can indeed improve processing efficiency and quality, compared with the steady flow.