The Theoretical And Experimental Study On The Dynamic Characteristics Of The Two-phase Flow In Planetary Finishing

As a high-efficiency piece of equipment, the centrifugal free lapping is used extensively for finishing and burring of some small, abnormal parts. In fact, some key parameters of design and technology of the centrifugal free lapping are decided by experience completely so far. But optimization of key parameters is impossibly realized by experiments merely. The kinematic characteristics of the abrasive fluid will be closely related to the quality and efficiency of workpiece in the centrifugal lapping, and the planetary driver ratio of the machine is an important parameter changing the fluid characteristics.Taking the kinematic mass abrasive as research object, this paper has analyzed theoretically and experimentally the influence of the planetary driver ratio in the processing of centrifugal polishing machine. It is pointed out that the profile of the abrasive and the path of the moving particles will be changed considerably with the alternation of planetary driver ratio. Furthermore, a series of experimental results show that the processing efficiency is affected prominently by the planetary drive ratio. The analysis conducted in this paper has put forward a proposal for improvement on the design of centrifugal polishing machine.Theoretically, a model of two phase fluid is used as to analyze the abrasive fluid characteristics at different planetary driver ratio. The shape figures, which illustrate the abrasive movement on typical planetary driver ratio and show the distribution of abrasive volume fraction and velocity, have been plotted by the method of computational fluid mechanics. The good accordance between the numerical simulation and the experimental result points out that numerous technical experiments can be substituted by numerical simulation with computer. By utilizing the numerical method, the parameters of design and technology can be optimized economically and efficiently, which can ultimately improve the productivity.High-speed photographing machine was employed to record the movement of abrasive flow in planetary abrasive flow processing in this paper. it is described that different planetary driver ratio on processing will bring on variational kinematic characteristics of the abrasive flow. Though qualitative analysis of the high-photograph, the movement of abrasive flow could be understood. It has been shown that the movement of the slippery layers and change of frontal interface curve are key factors affecting production efficiency and product quality. The fluid characteristics of the slippery layers can be changed obviously by altering planetary driver ratio. It will affect markedly the productivity of the machine. In the light of the experimental data, it has been explained that different planetary driver ratio will result in the change of abrasive shape. It can be seen that the flow feature of abrasives is a key factor of effecting productivity through analyzing the result of photographic experiment. Workpiece lapping experiment will verify the conclusion of photographic experiment in the light of the lapping quality of workpiece.