Beschreibung
In this work, a coupled particle approach is applied for the simulation of the cutting-fluid flow and chip evacuation in micro deep-hole drilling with different drill geometries. On the one hand, a helically shaped twist drill with a diameter of 5.0 mm is used and, on the other hand, a single-lip drill with a diameter of 2.0 mm. For the description of the cutting fluid the Smoothed Particle Hydrodynamics method is used while the Discrete Element Method is used for the description of solid bodies.
The first goal of this work is the transient simulation of the cutting-fluid flow with the Smoothed Particle Hydrodynamics method. As this particle method is comparatively young, the first part of this work focuses on the numerical background of the method and important current developments. Furthermore, it describes the methodical extensions selected and implemented for the simulations presented in this work.
Besides the obvious tasks of a fluid often called cooling lubricant, that is cooling and lubricating, the usage of cutting fluid is also crucial for the evacuation of chips, especially in the context of deep-hole drilling. Accordingly, the second goal of this work is the numerical description of chip evacuation due to the cutting-fluid with the two drill geometries.
The results of the presented simulations give insights into the macroscopic flow which are difficult or almost impossible to capture with metrological methods, especially in the bottom of the borehole or within the cooling channels. For example for the single-lip drill, a dead zone behind the outer cutting-edge is observed. Using the results from the twist-drill simulations a theoretical tool modification for the single-lip drill is presented that might help preventing the formation of such a dead zone.
