Transient Simulation of Cooling-Lubricant Flow for Deep-Hole Drilling-Processes

Schnabel, D.1, a; Özkaya, E.2, b; Biermann, D.2, c; Eberhard, P.1, d

1)
Institut für Technische und Numerische Mechanik, Universität Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart
2)
Institut für Spanende Fertigung, Technische Universität Dortmund, Baroper Str. 303, 44227 Dortmund

a) dirk.schnabel@itm.uni-stuttgart.de; b) oezkaya@isf.de; c) biermann@isf.de; d) peter.eberhard@itm.uni-stuttgart.de

Kurzfassung

Today, the process of single-lip deep-hole drilling becomes more and more important for many industrial applications, e.g. in aerospace engineering, automotive industry or for medical products. The cooling lubricant is not only most important for the quality of the resulting bore, but also for the evacuation of chips and for increasing the tool life. For that reason, a coupled particle approach for the simulation of cooling lubricant in the context of deep-hole drilling was developed. The cooling lubricant in the presented simulations is described by the Smoothed Particle Hydrodynamics method and the drill chips are described by Discrete Element multispheres. From the performed simulations, one can see that the coupled particle methods together with meshbased Computational Fluid Dynamics simulations are suitable for the description of the flow field and the chip evacuation. Furthermore, the simulations of the cooling lubricant for a single-lip drill show a velocity sink behind the cutting edge at the tip of the drilling tool. This result indicates great potential for the optimization of the tool geometry, presumably leading to an increased tool life as well as an improved cooling behaviour. Considering inlet pressures above 20 bar, and a drill diameter of 2 mm, the presented systems are challenging, with particle velocities above 100 m/s. However, the results of the performed simulations show a great potential for the application of coupled particle methods and meshbased Computational Fluid Dynamics for the investigation of the coolant flow. It can be seen that the Smoothed Particle Hydrodynamics method is an interesting alternative compared to meshbased methods, due to its property to describe the transient evolution of the cooling lubricant without any special treatment of free surfaces and interfaces that experience great topological changes. Especially for simulations which do not assume the evacuation channel to be entirely filled with cooling lubricant, the meshless nature of particle methods is beneficial.

Schlüsselwörter

Cooling-Lubricant, Chip Evacuation, CFD, SPH, Coupled Particle-Methods

Veröffentlichung

Procedia CIRP, 77 (2018), S. 78-81, doi: 10.1016/j.procir.2018.08.224