Thorsten Helmig, Tim Göttlich, Hui Liu, Thomas Bergs, Reinhold Kneer

Abstract: The thermal modeling of machine processes is a key tool to enhance product quality and surface integrity for high precision components. In this context, the cutting zone is of particular interest as significant stresses, temperature gradients and heat sources occur. To accurately model these processes, an FEM-CFD coupling has been developed. In the first step, a FEM chip formation simulation is performed which uses cutting parameters, material models, and mechanical properties. The FEM simulation is performed for an Inconel 718 workpiece. Afterwards, the generated chip geometry, temperature field, and heat source are transferred into a CFD model which quantifies the conjugate heat transfer and corresponding convective heat transfer coefficients at the fluid-solid interface. As recently published work focuses on the development and validation of the interface itself, the work at hand studies the impact of evolving chip geometry on convective heat transfer. Therefore, the continuously evolving chip is approximated by discretizing the geometry development into constant states. Moreover, the investigations are performed in context of a quasi-stationary problem meaning that the tool has performed several cuts and already reached a steady-state temperature field. The analysis shows that the chip has a significant impact on local heat transfer revealing further the heat transfer can be subdivided into two regions: First, a near cutting edge region where chip geometry and fluid temperature impact the heat transfer and second a tool downstream region, where the fluid temperature is the dominating parameter. In total, these results can be used as a basis for future cooling optimization studies.

Keywords: Computational Fluid Dynamics, Conjugate Heat Transfer, Machining Processes, Orthogonal Cutting, Evolving Chip Geometry

Date Published: November 7, 2022
DOI: 10.11159/jffhmt.2022.021

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